[Kafka API] Add forwarding of txn requests to coordinator

[a-serebryanskiy]

Changelog entry

Small PR adding the forwarding of transaction related requests from kafka connection to transaction coordinator.

Changelog category

• Not for changelog (changelog entry is not required)

Description for reviewers

...

[github-actions]

🟢 2025-04-26 16:21:59 UTC The validation of the Pull Request description is successful.

[github-actions]

⚪ 2025-04-26 16:22:30 UTC Pre-commit check linux-x86_64-relwithdebinfo for b3441d2 has started.
⚪ 2025-04-26 16:23:02 UTC Artifacts will be uploaded here
⚪ 2025-04-26 16:25:47 UTC ya make is running...
🟡 2025-04-26 17:42:35 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?
22103	20729	0	11	1323	40

⚪ 2025-04-26 17:44:31 UTC ya make is running... (failed tests rerun, try 2)
🟢 2025-04-26 18:13:47 UTC Tests successful.

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

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
176 (only retried tests)	129	0	0	14	33

🟢 2025-04-26 18:13:54 UTC Build successful.
🟢 2025-04-26 18:14:13 UTC ydbd size 2.2 GiB changed* by +23.1 KiB, which is < 100.0 KiB vs main: OK

ydbd size dash	main: 290386c	merge: b3441d2	diff	diff %
ydbd size	2 342 188 048 Bytes	2 342 211 704 Bytes	+23.1 KiB	+0.001%
ydbd stripped size	492 592 192 Bytes	492 596 352 Bytes	+4.1 KiB	+0.001%

^{*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]

⚪ 2025-04-26 16:22:52 UTC Pre-commit check linux-x86_64-release-asan for b3441d2 has started.
⚪ 2025-04-26 16:23:07 UTC Artifacts will be uploaded here
⚪ 2025-04-26 16:26:01 UTC ya make is running...
🟡 2025-04-26 17:47:37 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?
14347	14191	0	92	39	25

⚪ 2025-04-26 17:48:51 UTC ya make is running... (failed tests rerun, try 2)
🟡 2025-04-26 18:17:41 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?
1394 (only retried tests)	1282	0	49	39	24

⚪ 2025-04-26 18:17:58 UTC ya make is running... (failed tests rerun, try 3)
🟡 2025-04-26 18:46:35 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?
792 (only retried tests)	698	0	48	23	23

🟢 2025-04-26 18:46:45 UTC Build successful.
🟢 2025-04-26 18:47:17 UTC ydbd size 3.8 GiB changed* by +48.5 KiB, which is < 100.0 KiB vs main: OK

ydbd size dash	main: 290386c	merge: b3441d2	diff	diff %
ydbd size	4 120 274 248 Bytes	4 120 323 896 Bytes	+48.5 KiB	+0.001%
ydbd stripped size	1 428 517 272 Bytes	1 428 534 776 Bytes	+17.1 KiB	+0.001%

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