Extract TIndexBuildInfo into a separate file

[vitalif]

Changelog category

• Not for changelog (changelog entry is not required)

Description for reviewers

Перезапушил заново из #30474 сюда отдельно вынос TIndexBuildInfo, т.к. там прилипли columnshard, хотя именно в выносе IndexBuildInfo их нет

[ydbot]

Run Extra Tests

Run additional tests for this PR. You can customize:

• Test Size: small, medium, large (default: all)
• Test Targets: any directory path (default: ydb/)
• Sanitizers: ASAN, MSAN, TSAN
• Coredumps: enable for debugging (default: off)
• Additional args: custom ya make arguments

[github-actions]

🟢 2025-12-10 16:08:36 UTC The validation of the Pull Request description is successful.

[github-actions]

⚪ 2025-12-10 16:21:13 UTC Pre-commit check linux-x86_64-relwithdebinfo for bf86e62 has started.
⚪ 2025-12-10 16:23:28 UTC Artifacts will be uploaded here
⚪ 2025-12-10 16:25:30 UTC ya make is running...
🟡 2025-12-10 18:00:31 UTC Some tests failed, follow the links below. Going to retry failed tests...

Details

Ya make output | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
40128	37037	0	5	3062	24

⚪ 2025-12-10 18:00:46 UTC ya make is running... (failed tests rerun, try 2)
🟢 2025-12-10 18:20:36 UTC Tests successful.

Ya make output | Test bloat | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
284 (only retried tests)	192	0	0	76	16

🟢 2025-12-10 18:20:43 UTC Build successful.
🟢 2025-12-10 18:21:13 UTC ydbd size 2.3 GiB changed* by +71.6 KiB, which is < 100.0 KiB vs main: OK

ydbd size dash	main: 70147ba	merge: bf86e62	diff	diff %
ydbd size	2 468 459 016 Bytes	2 468 532 288 Bytes	+71.6 KiB	+0.003%
ydbd stripped size	525 272 448 Bytes	525 271 936 Bytes	-512 Bytes	-0.000%

^{*please be aware that the difference is based on comparing your commit and the last completed build from the post-commit, check comparation}

[github-actions]

⚪ 2025-12-10 16:21:27 UTC Pre-commit check linux-x86_64-release-asan for bf86e62 has started.
⚪ 2025-12-10 16:23:13 UTC Artifacts will be uploaded here
⚪ 2025-12-10 16:25:11 UTC ya make is running...
🟡 2025-12-10 17:28:09 UTC Some tests failed, follow the links below. This fail is not in blocking policy yet

Ya make output | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
11968	11900	0	54	7	7

🟢 2025-12-10 17:28:18 UTC Build successful.
🟢 2025-12-10 17:29:03 UTC ydbd size 3.8 GiB changed* by +84.2 KiB, which is < 100.0 KiB vs main: OK

ydbd size dash	main: 70147ba	merge: bf86e62	diff	diff %
ydbd size	4 133 543 176 Bytes	4 133 629 384 Bytes	+84.2 KiB	+0.002%
ydbd stripped size	1 534 296 120 Bytes	1 534 299 480 Bytes	+3.3 KiB	+0.000%

^{*please be aware that the difference is based on comparing your commit and the last completed build from the post-commit, check comparation}

[ydbot]

Backport

To backport this PR, click the button next to the target branch and then click "Run workflow" in the Run Actions UI.

Branch	Run
stable-25-2, stable-25-2-1, stable-25-3, stable-25-3-1
stable-25-3, stable-25-3-1
stable-25-3