Improve KqpHost introspection, add KqpExecuter and CA virtual pages

[Hor911]

#30184

[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]

🟢 2025-12-05 11:52:02 UTC The validation of the Pull Request description is successful.

[github-actions]

⚪ 2025-12-05 11:52:14 UTC Pre-commit check linux-x86_64-release-asan for d5033de has started.
⚪ 2025-12-05 11:52:31 UTC Artifacts will be uploaded here
⚪ 2025-12-05 11:54:47 UTC ya make is running...
🟡 2025-12-05 13:02:18 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?
11715	11576	0	121	8	10

🟢 2025-12-05 13:02:28 UTC Build successful.
🟡 2025-12-05 13:02:55 UTC ydbd size 3.8 GiB changed* by +203.8 KiB, which is >= 100.0 KiB vs main: Warning

ydbd size dash	main: 1a44fbc	merge: d5033de	diff	diff %
ydbd size	4 125 642 096 Bytes	4 125 850 824 Bytes	+203.8 KiB	+0.005%
ydbd stripped size	1 532 051 096 Bytes	1 532 118 232 Bytes	+65.6 KiB	+0.004%

^{*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]

⚪ 2025-12-05 11:52:53 UTC Pre-commit check linux-x86_64-relwithdebinfo for d5033de has started.
⚪ 2025-12-05 11:53:09 UTC Artifacts will be uploaded here
⚪ 2025-12-05 11:55:17 UTC ya make is running...
🟡 2025-12-05 13:21:58 UTC Some tests failed, follow the links below. Going to retry failed tests...

Ya make output | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
31941	30499	0	4	1416	22

⚪ 2025-12-05 13:22:09 UTC ya make is running... (failed tests rerun, try 2)
🟢 2025-12-05 13:31:03 UTC Tests successful.

Ya make output | Test bloat | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
49 (only retried tests)	36	0	0	0	13

🟢 2025-12-05 13:31:10 UTC Build successful.
🟡 2025-12-05 13:31:29 UTC ydbd size 2.3 GiB changed* by +137.4 KiB, which is >= 100.0 KiB vs main: Warning

ydbd size dash	main: 1a44fbc	merge: d5033de	diff	diff %
ydbd size	2 465 266 112 Bytes	2 465 406 824 Bytes	+137.4 KiB	+0.006%
ydbd stripped size	524 713 088 Bytes	524 743 680 Bytes	+29.9 KiB	+0.006%

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