[OLAP Projection pushdown] Do not push projection if kqp expects a full json document from CS

[denis0x0D]

Changelog entry

Fix for #26437

Changelog category

• Bugfix

Description for reviewers

#26437

[github-actions]

⚪ 2025-10-24 13:00:16 UTC Pre-commit check linux-x86_64-relwithdebinfo for 31dbfed has started.
⚪ 2025-10-24 13:00:32 UTC Artifacts will be uploaded here
⚪ 2025-10-24 13:04:03 UTC ya make is running...
🟡 2025-10-24 14:50:24 UTC Some tests failed, follow the links below. Going to retry failed tests...

Ya make output | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
38670	35874	0	5	2764	27

⚪ 2025-10-24 14:50:34 UTC ya make is running... (failed tests rerun, try 2)
🟢 2025-10-24 15:17:00 UTC Tests successful.

Ya make output | Test bloat | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
441 (only retried tests)	418	0	0	0	23

🟢 2025-10-24 15:17:03 UTC Build successful.
🟢 2025-10-24 15:17:20 UTC ydbd size 2.3 GiB changed* by +14.8 KiB, which is < 100.0 KiB vs main: OK

ydbd size dash	main: 4a034a5	merge: 31dbfed	diff	diff %
ydbd size	2 437 318 736 Bytes	2 437 333 840 Bytes	+14.8 KiB	+0.001%
ydbd stripped size	518 126 792 Bytes	518 130 184 Bytes	+3.3 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]

⚪ 2025-10-24 13:00:21 UTC Pre-commit check linux-x86_64-release-asan for 31dbfed has started.
⚪ 2025-10-24 13:00:36 UTC Artifacts will be uploaded here
⚪ 2025-10-24 13:04:18 UTC ya make is running...
🟡 2025-10-24 15:12:47 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?
15692	15227	0	198	246	21

🟢 2025-10-24 15:12:53 UTC Build successful.
🟢 2025-10-24 15:13:17 UTC ydbd size 3.8 GiB changed* by +45.8 KiB, which is < 100.0 KiB vs main: OK

ydbd size dash	main: 4a034a5	merge: 31dbfed	diff	diff %
ydbd size	4 055 678 288 Bytes	4 055 725 168 Bytes	+45.8 KiB	+0.001%
ydbd stripped size	1 506 013 440 Bytes	1 506 030 528 Bytes	+16.7 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]

🟢 2025-10-24 13:00:42 UTC The validation of the Pull Request description is successful.