feat(emerge): Add git info to frontend

[rbro112]

[rbro112]

• feat(emerge): Add git info to frontend #97457 👈 (View in Graphite)
• feat(emerge): Add new vcs fields to buildDetails API #97456
• feat(preprod): Add new vcs related fields to preprod artifact assemble endpoint #97332
• master

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[codecov]

❌ 1 Tests Failed:

Tests completed	Failed	Passed	Skipped
11323	1	11322	10

View the top 1 failed test(s) by shortest run time

useReplayCount getMany & hasMany should return 0 if the data is loaded but does not include a count for a requested id

Stack Traces | 0.686s run time

Error: expect(received).toStrictEqual(expected) // deep equality

- Expected  - 4
+ Received  + 1

- Object {
-   "1111": 0,
-   "2222": 7,
- }
+ Object {}
    at Object.toStrictEqual (.../utils/replayCount/useReplayCount.spec.tsx:166:56)
    at runNextTicks (node:internal/process/task_queues:65:5)
    at listOnTimeout (node:internal/timers:549:9)
    at processTimers (node:internal/timers:523:7)

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[cursor]

Bug: VCS Info Access and PR Number Type Issues

The commit introduces two issues:

1. Optional chaining was removed from vcs_info object accesses, potentially causing runtime errors if vcs_info is null or undefined.
2. The pr_number field has a type inconsistency, returning number or string ('-') instead of consistently string, unlike other fields. It should be explicitly converted to a string.