[ICRDMA] Do not scan devices from ctor. Restore ut. EXT-1639

[dcherednik]

Changelog entry

Access to ibverbs library from ctor of LinkManager causes issue with msan for whole project. To solve it we will initialise rdma context only if it needed. Msan tests will not be run for rdma related code.

Changelog category

• Not for changelog (changelog entry is not required)

Description for reviewers

...

[github-actions]

🟢 2025-10-31 13:53:55 UTC The validation of the Pull Request description is successful.

[github-actions]

⚪ 2025-10-31 11:43:51 UTC Pre-commit check linux-x86_64-release-asan for 341f573 has started.
⚪ 2025-10-31 11:44:09 UTC Artifacts will be uploaded here
⚪ 2025-10-31 11:45:30 UTC ya make is running...
🟡 2025-10-31 13:45:42 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?
17981	17557	0	155	249	20

🟢 2025-10-31 13:45:48 UTC Build successful.
🟢 2025-10-31 13:46:14 UTC ydbd size 3.8 GiB changed* by +79.4 KiB, which is < 100.0 KiB vs main: OK

ydbd size dash	main: a04e6ba	merge: 341f573	diff	diff %
ydbd size	4 063 322 088 Bytes	4 063 403 376 Bytes	+79.4 KiB	+0.002%
ydbd stripped size	1 508 300 152 Bytes	1 508 327 928 Bytes	+27.1 KiB	+0.002%

^{*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]

⚪ 2025-10-31 11:43:58 UTC Pre-commit check linux-x86_64-relwithdebinfo for 341f573 has started.
⚪ 2025-10-31 11:44:15 UTC Artifacts will be uploaded here
⚪ 2025-10-31 11:45:40 UTC ya make is running...
🟡 2025-10-31 13:26:22 UTC Some tests failed, follow the links below. Going to retry failed tests...

Ya make output | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
41701	38859	0	5	2803	34

⚪ 2025-10-31 13:26:39 UTC ya make is running... (failed tests rerun, try 2)
🟢 2025-10-31 13:37:42 UTC Tests successful.

Ya make output | Test bloat | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
80 (only retried tests)	65	0	0	0	15

🟢 2025-10-31 13:37:44 UTC Build successful.
🟢 2025-10-31 13:38:01 UTC ydbd size 2.3 GiB changed* by +35.4 KiB, which is < 100.0 KiB vs main: OK

ydbd size dash	main: a04e6ba	merge: 341f573	diff	diff %
ydbd size	2 426 565 360 Bytes	2 426 601 568 Bytes	+35.4 KiB	+0.001%
ydbd stripped size	515 718 280 Bytes	515 718 280 Bytes	0 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}