Auto merge of #108148 - parthopdas:master, r=oli-obk

Implementing "<test_binary> --list --format json" for use by IDE test explorers / runners

Fixes #107307

PR 1 of 2 - wiring up just the new information + implement the command line changes i.e. --format json + tests

upcoming:
PR 2 of 2 - clean up "#[cfg(not(bootstrap))]" from PR 1

As per the discussions on
- MCP: https://rust-lang.zulipchat.com/#narrow/stream/233931-t-compiler.2Fmajor-changes/topic/Implementing.20.22.3Ctest_binary.3E.20--list.20--form.E2.80.A6.20compiler-team.23592/near/328747548
- preRFC: https://internals.rust-lang.org/t/pre-rfc-implementing-test-binary-list-format-json-for-use-by-ide-test-explorers-runners/18308
- FYI on Discord: https://discord.com/channels/442252698964721669/459149169546887178/1075581549409484820

Author: bors