Use the whole TTableDescription to describe an indexImplTable in TIndexDescription (#6280)

[jepett0]

Relevant ticket
PR into main

The purpose of the change is to prepare for multiple indexImplTables for vector indices. Other changes are more or less cosmetic.

We need to merge these change in the stable-24-3 branch, before it starts to roll out on the actual clusters, because these changes are BREAKING (see protobuf).

[github-actions]

⚪ 2024-07-09 07:22:51 UTC Pre-commit check for ac02a9a has started.
⚪ 2024-07-09 07:25:41 UTC Build linux-x86_64-release-asan is running...
🟢 2024-07-09 08:10:00 UTC Build successful.
⚪ 2024-07-09 08:10:12 UTC Tests are running...
🔴 2024-07-09 10:08:32 UTC Some tests failed, follow the links below.

Test history | Test log

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
11227	10644	0	90	320	173

🟢 2024-07-09 10:09:14 UTC ydbd size 5.2 GiB changed* by -2.5 KiB, which is <= 0 Bytes vs stable-24-3: OK

ydbd size dash	stable-24-3: 44a1cd0	merge: ac02a9a	diff	diff %
ydbd size	5 615 664 240 Bytes	5 615 661 688 Bytes	-2.5 KiB	-0.000%
ydbd stripped size	1 211 071 912 Bytes	1 211 077 896 Bytes	+5.8 KiB	+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]

⚪ 2024-07-09 07:26:33 UTC Pre-commit check for ac02a9a has started.
⚪ 2024-07-09 07:29:27 UTC Build linux-x86_64-release-clang14 is running...
🟢 2024-07-09 08:06:50 UTC Build successful.

[github-actions]

⚪ 2024-07-09 07:28:44 UTC Pre-commit check for ac02a9a has started.
⚪ 2024-07-09 07:32:04 UTC Build linux-x86_64-relwithdebinfo is running...
🟢 2024-07-09 08:33:28 UTC Build successful.
⚪ 2024-07-09 08:33:47 UTC Tests are running...
🔴 2024-07-09 10:26:54 UTC Some tests failed, follow the links below.

Test history | Test log

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
39742	34493	0	14	5222	13

🟢 2024-07-09 10:27:34 UTC ydbd size 8.1 GiB changed* by -192 Bytes, which is <= 0 Bytes vs stable-24-3: OK

ydbd size dash	stable-24-3: 44a1cd0	merge: ac02a9a	diff	diff %
ydbd size	8 725 589 248 Bytes	8 725 589 056 Bytes	-192 Bytes	-0.000%
ydbd stripped size	477 140 648 Bytes	477 138 568 Bytes	-2.0 KiB	-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}