25-1: Support an emergency one-to-one split/merge in SchemeShard

[snaury]

Changelog entry

...

Changelog category

• Not for changelog (changelog entry is not required)

Description for reviewers

Add a special one-to-one split/merge mode in SchemeShard to use in an emergency, e.g. when we need to garbage collect data that is not accounted by tablets but occupies storage space.

Merges #17642.

[github-actions]

🟢 2025-04-24 07:44:09 UTC The validation of the Pull Request description is successful.

[github-actions]

⚪ 2025-04-24 07:44:11 UTC Pre-commit check linux-x86_64-relwithdebinfo for d49de8b has started.
⚪ 2025-04-24 07:44:27 UTC Artifacts will be uploaded here
⚪ 2025-04-24 07:47:50 UTC ya make is running...
🔴 2025-04-24 08:00:51 UTC Build failed, see the logs. Also see fail summary

[github-actions]

⚪ 2025-04-24 07:44:11 UTC Pre-commit check linux-x86_64-release-asan for d49de8b has started.
⚪ 2025-04-24 07:44:27 UTC Artifacts will be uploaded here
⚪ 2025-04-24 07:47:44 UTC ya make is running...
🔴 2025-04-24 08:01:40 UTC Build failed, see the logs. Also see fail summary

[github-actions]

⚪ 2025-04-24 08:20:12 UTC Pre-commit check linux-x86_64-relwithdebinfo for 8962259 has started.
⚪ 2025-04-24 08:20:27 UTC Artifacts will be uploaded here
⚪ 2025-04-24 08:23:45 UTC ya make is running...
🟡 2025-04-24 09:59:54 UTC Some tests failed, follow the links below. Going to retry failed tests...

Test history | Ya make output | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
28224	25618	0	2	2471	133

⚪ 2025-04-24 10:02:17 UTC ya make is running... (failed tests rerun, try 2)
🟢 2025-04-24 10:24:32 UTC Tests successful.

Test history | Ya make output | Test bloat | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
211 (only retried tests)	81	0	0	2	128

🟢 2025-04-24 10:24:42 UTC Build successful.
🟢 2025-04-24 10:25:00 UTC ydbd size 2.1 GiB changed* by +76.4 KiB, which is < 100.0 KiB vs stable-25-1: OK

ydbd size dash	stable-25-1: bdcb555	merge: 8962259	diff	diff %
ydbd size	2 244 895 200 Bytes	2 244 973 448 Bytes	+76.4 KiB	+0.003%
ydbd stripped size	475 303 480 Bytes	475 315 960 Bytes	+12.2 KiB	+0.003%

^{*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]

⚪ 2025-04-24 08:21:42 UTC Pre-commit check linux-x86_64-release-asan for 8962259 has started.
⚪ 2025-04-24 08:22:09 UTC Artifacts will be uploaded here
⚪ 2025-04-24 08:25:59 UTC ya make is running...
🟡 2025-04-24 10:11:00 UTC Some tests failed, follow the links below. This fail is not in blocking policy yet Going to retry failed tests...

Test history | Ya make output | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
14030	13897	0	45	53	35

⚪ 2025-04-24 10:12:17 UTC ya make is running... (failed tests rerun, try 2)
🟡 2025-04-24 10:32:49 UTC Some tests failed, follow the links below. This fail is not in blocking policy yet Going to retry failed tests...

Test history | Ya make output | Test bloat | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
178 (only retried tests)	92	0	6	48	32

⚪ 2025-04-24 10:32:58 UTC ya make is running... (failed tests rerun, try 3)
🟡 2025-04-24 10:53:06 UTC Some tests failed, follow the links below. This fail is not in blocking policy yet

Test history | Ya make output | Test bloat | Test bloat | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
112 (only retried tests)	30	0	6	44	32

🟢 2025-04-24 10:53:13 UTC Build successful.
🟡 2025-04-24 10:53:40 UTC ydbd size 3.6 GiB changed* by +125.7 KiB, which is >= 100.0 KiB vs stable-25-1: Warning

ydbd size dash	stable-25-1: bdcb555	merge: 8962259	diff	diff %
ydbd size	3 905 044 160 Bytes	3 905 172 864 Bytes	+125.7 KiB	+0.003%
ydbd stripped size	1 366 300 176 Bytes	1 366 336 144 Bytes	+35.1 KiB	+0.003%

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