Improve brigded group proxy a bit

[alexvru]

Changelog entry

Improve brigded group proxy a bit

Changelog category

• Not for changelog (changelog entry is not required)

Description for reviewers

This patch introduces some refactoring into bridged group proxy.

[github-actions]

🟢 2025-09-10 05:06:05 UTC The validation of the Pull Request description is successful.

[github-actions]

⚪ 2025-09-10 05:06:15 UTC Pre-commit check linux-x86_64-relwithdebinfo for 013fea0 has started.
⚪ 2025-09-10 05:07:07 UTC Artifacts will be uploaded here
⚪ 2025-09-10 05:11:10 UTC ya make is running...
🟡 2025-09-10 06:28:46 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?
31165	29755	0	7	1369	34

⚪ 2025-09-10 06:31:28 UTC ya make is running... (failed tests rerun, try 2)
🟢 2025-09-10 06:44:37 UTC Tests successful.

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

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
255 (only retried tests)	234	0	0	0	21

🟢 2025-09-10 06:44:46 UTC Build successful.
🟢 2025-09-10 06:45:02 UTC ydbd size 2.3 GiB changed* by +30.2 KiB, which is < 100.0 KiB vs main: OK

ydbd size dash	main: 16e97fd	merge: 013fea0	diff	diff %
ydbd size	2 465 039 288 Bytes	2 465 070 184 Bytes	+30.2 KiB	+0.001%
ydbd stripped size	515 200 296 Bytes	515 204 456 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]

⚪ 2025-09-10 05:06:16 UTC Pre-commit check linux-x86_64-release-asan for 013fea0 has started.
⚪ 2025-09-10 05:06:22 UTC Artifacts will be uploaded here
⚪ 2025-09-10 05:09:44 UTC ya make is running...
🟡 2025-09-10 07:04:04 UTC Some tests failed, follow the links below. This fail is not in blocking policy yet

Test history | Ya make output | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
15510	15088	0	135	265	22

🟢 2025-09-10 07:05:23 UTC Build successful.
🟢 2025-09-10 07:05:46 UTC ydbd size 4.0 GiB changed* by +40.6 KiB, which is < 100.0 KiB vs main: OK

ydbd size dash	main: 16e97fd	merge: 013fea0	diff	diff %
ydbd size	4 312 138 640 Bytes	4 312 180 232 Bytes	+40.6 KiB	+0.001%
ydbd stripped size	1 491 553 016 Bytes	1 491 569 272 Bytes	+15.9 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}