feat: add new uiconfig route

[mfrancisc]

This PR adds a new route GET /api/v1/uiconfig which will return configuration values to be used by the frontend applications.

Right now there is only one ( temporary ) config value : UICanaryDeploymentWeight which is being retrieved from the toolchainconfig.Host.RegistrationService.UICanaryDeploymentWeight. In the future we might have more values we want to configure that will change the behaviour of the UI.

Jira: https://issues.redhat.com/browse/SANDBOX-1144

Related to:
api: codeready-toolchain/api#476

[codecov]

Codecov Report

Attention: Patch coverage is 83.33333% with 2 lines in your changes missing coverage. Please review.

Project coverage is 81.11%. Comparing base (c1faae6) to head (3bb3b53).
Report is 1 commits behind head on master.

Files with missing lines	Patch %	Lines
pkg/configuration/configuration.go	0.00%	2 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #530   +/-   ##
=======================================
  Coverage   81.10%   81.11%           
=======================================
  Files          43       44    +1     
  Lines        3520     3532   +12     
=======================================
+ Hits         2855     2865   +10     
- Misses        578      580    +2     
  Partials       87       87           

Flag	Coverage Δ
unittests	81.11% <83.33%> (+<0.01%)	⬆️

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[openshift-ci]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: alexeykazakov, mfrancisc

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

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

See analysis details on SonarQube Cloud