Rename RowCount => ChunkCount to align with semantics and make it less confusing

[Hor911]

#15105

TPC-H Q1, mixed cluster

From old node:

From new node:

both are correct

[github-actions]

🟢 2025-02-27 15:56:20 UTC The validation of the Pull Request description is successful.

[github-actions]

⚪ 2025-02-26 14:41:55 UTC Pre-commit check linux-x86_64-release-asan for 899dd6c has started.
⚪ 2025-02-26 14:42:10 UTC Artifacts will be uploaded here
⚪ 2025-02-26 14:45:34 UTC ya make is running...
🔴 2025-02-26 14:51:33 UTC Build failed, see the logs. Also see fail summary

[github-actions]

⚪ 2025-02-26 14:44:00 UTC Pre-commit check linux-x86_64-relwithdebinfo for 899dd6c has started.
⚪ 2025-02-26 14:44:16 UTC Artifacts will be uploaded here
⚪ 2025-02-26 14:47:37 UTC ya make is running...
🔴 2025-02-26 14:52:01 UTC Build failed, see the logs. Also see fail summary

[github-actions]

⚪ 2025-02-26 16:22:47 UTC Pre-commit check linux-x86_64-relwithdebinfo for 1c9ca64 has started.
⚪ 2025-02-26 16:23:05 UTC Artifacts will be uploaded here
⚪ 2025-02-26 16:26:17 UTC ya make is running...
🟡 2025-02-26 17:49:39 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?
28283	25675	0	3	2476	129

⚪ 2025-02-26 17:52:37 UTC ya make is running... (failed tests rerun, try 2)
🟢 2025-02-26 18:03:16 UTC Tests successful.

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

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
208 (only retried tests)	84	0	0	0	124

🟢 2025-02-26 18:03:29 UTC Build successful.
🟢 2025-02-26 18:03:47 UTC ydbd size 2.1 GiB changed* by +32 Bytes, which is < 100.0 KiB vs main: OK

ydbd size dash	main: 60c4deb	merge: 1c9ca64	diff	diff %
ydbd size	2 284 790 840 Bytes	2 284 790 872 Bytes	+32 Bytes	+0.000%
ydbd stripped size	479 196 832 Bytes	479 196 832 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}

[github-actions]

⚪ 2025-02-26 16:23:54 UTC Pre-commit check linux-x86_64-release-asan for 1c9ca64 has started.
⚪ 2025-02-26 16:24:10 UTC Artifacts will be uploaded here
⚪ 2025-02-26 16:27:20 UTC ya make is running...
🟡 2025-02-26 18:07:52 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?
13897	13739	0	100	24	34

⚪ 2025-02-26 18:09:25 UTC ya make is running... (failed tests rerun, try 2)
🟡 2025-02-26 18:24:25 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?
221 (only retried tests)	187	0	7	0	27

⚪ 2025-02-26 18:24:34 UTC ya make is running... (failed tests rerun, try 3)
🟡 2025-02-26 18:35:39 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?
64 (only retried tests)	35	0	2	0	27

🟢 2025-02-26 18:35:46 UTC Build successful.
🟢 2025-02-26 18:36:15 UTC ydbd size 3.7 GiB changed* by -32 Bytes, which is <= 0 Bytes vs main: OK

ydbd size dash	main: 60c4deb	merge: 1c9ca64	diff	diff %
ydbd size	3 982 279 136 Bytes	3 982 279 104 Bytes	-32 Bytes	-0.000%
ydbd stripped size	1 387 041 448 Bytes	1 387 041 384 Bytes	-64 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}

[Hor911]

Import build check https://nda.ya.ru/t/2e2cCUjZ7CKeHG