feat: update route mechanism

[Alanxtl]

ref: #699
update content can refer to: https://github.com/Alanxtl/pixiu-router-update

benchmark result:

goos: windows
goarch: amd64
pkg: github.com/apache/dubbo-go-pixiu/pkg/common/router
cpu: AMD Ryzen 7 5800H with Radeon Graphics         
BenchmarkRouteReadThroughput/old/locked-read-30k-16                 7089            170887 ns/op           14797 B/op          7 allocs/op
BenchmarkRouteReadThroughput/new/rcu-read-30k-16                   25041             47645 ns/op             309 B/op          6 allocs/op
BenchmarkRouteReadParallel/old/parallel-30k-16                     45613             28601 ns/op           14824 B/op          7 allocs/op
BenchmarkRouteReadParallel/new/parallel-30k-16                    171332              8965 ns/op             310 B/op          6 allocs/op
BenchmarkReloadLatency/old/reload-1percent-30k-16                   1628            682656 ns/op          635355 B/op       6378 allocs/op
BenchmarkReloadLatency/new/reload-1percent-30k-16                   5469            214520 ns/op          301038 B/op        902 allocs/op
BenchmarkRoute100kReadThroughput/old/locked-read-100k-16            1218           1008264 ns/op           62400 B/op          8 allocs/op
BenchmarkRoute100kReadThroughput/new/rcu-read-100k-16               7696            164474 ns/op             310 B/op          6 allocs/op
BenchmarkRoute100kReadParallel/old/parallel-100k-16                10000            116339 ns/op           63567 B/op          8 allocs/op
BenchmarkRoute100kReadParallel/new/parallel-100k-16                56233             20846 ns/op             308 B/op          6 allocs/op
BenchmarkReload100kLatency1Percent/old/reload-1percent-100k-16               541           2267304 ns/op         2064730 B/op      21063 allocs/op
BenchmarkReload100kLatency1Percent/new/reload-1percent-100k-16              1419            796151 ns/op          973764 B/op       3001 allocs/op
BenchmarkRouteByPathAndName/old/RouteByPathAndName-16                    1231768               933.6 ns/op           429 B/op          9 allocs/op
BenchmarkRouteByPathAndName/new/RouteByPathAndName-16                    1419300               797.3 ns/op           429 B/op          9 allocs/op
PASS
ok      github.com/apache/dubbo-go-pixiu/pkg/common/router      24.883s

[codecov-commenter]

Codecov Report

❌ Patch coverage is 31.06509% with 233 lines in your changes missing coverage. Please review.
✅ Project coverage is 15.81%. Comparing base (26606a8) to head (ba1ab0d).
⚠️ Report is 73 commits behind head on develop.

Files with missing lines	Patch %	Lines
pkg/model/router_snapshot.go	0.00%	100 Missing ⚠️
pkg/common/router/mock/router.go	0.00%	89 Missing ⚠️
pkg/common/router/router.go	84.67%	14 Missing and 5 partials ⚠️
pkg/common/util/stringutil/stringutil.go	0.00%	19 Missing ⚠️
pkg/model/router.go	0.00%	6 Missing ⚠️

❗ There is a different number of reports uploaded between BASE (26606a8) and HEAD (ba1ab0d). Click for more details.

HEAD has 1 upload less than BASE

Flag	BASE (26606a8)	HEAD (ba1ab0d)
	1	0

Additional details and impacted files

@@             Coverage Diff              @@
##           develop     #777       +/-   ##
============================================
- Coverage    54.67%   15.81%   -38.86%     
============================================
  Files          671      222      -449     
  Lines        78658    16628    -62030     
============================================
- Hits         43006     2630    -40376     
+ Misses       31981    13760    -18221     
+ Partials      3671      238     -3433     

Flag	Coverage Δ
unittests	15.81% <31.06%> (?)

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[sonarqubecloud]

Quality Gate passed

Issues
9 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
4.7% Duplication on New Code

See analysis details on SonarQube Cloud

[Copilot]

Pull Request Overview

This PR implements a new routing mechanism to improve performance by replacing the locked read/write approach with a Read-Copy-Update (RCU) pattern using atomic snapshots. The changes include introducing a snapshot-based routing system with debounced updates and optimized data structures.

Key changes:

• Replaced mutex-based route coordination with atomic snapshot pattern
• Added debounced route updates to batch changes and reduce overhead
• Introduced optimized snapshot data structures with pre-compiled regex and method-specific tries

Reviewed Changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
pkg/model/router_snapshot.go	New snapshot data structures and compilation logic for lock-free routing
pkg/model/router.go	Minor comment corrections and enhanced string representation for header-only routes
pkg/common/util/stringutil/stringutil.go	Added utility function for generating trie keys with prefix support
pkg/common/router/router_test.go	Comprehensive test suite comparing old vs new router implementations
pkg/common/router/router_bench_test.go	Performance benchmarks demonstrating improvements in throughput and latency
pkg/common/router/router.go	Complete rewrite of router coordinator using atomic snapshots and debounced updates
pkg/common/router/mock/router.go	Mock implementation preserving old router behavior for comparison testing
pkg/common/http/manager_test.go	Updated test configurations to use new router structure
pkg/common/constant/http.go	Added constant for header value all levels pattern

---

_{Tip: Customize your code reviews with copilot-instructions.md. Create the file or learn how to get started.}