txn: change lock into put record for unique index key lock

[cfzjywxk]

What problem does this PR solve?

Issue Number:
Related to #25659

Problem Summary:
Since #21229, all the unique index keys will be locked if they are used in the for update read access path. The for update read with point get on non-clusetered unique index keys may leave many LOCK records which affect the performance a lot.

What is changed and how it works?

What's Changed:
Change the LOCK record into PUT when the for update read is used for point/batch point get unqiue index read.
Record the original index value into memory buffer so that the record will be PUT.

How it Works:

Related changes

• Need to cherry-pick to the release branch

Check List

Tests

• Unit test

Side effects

• Put more data into storage when the unique key index is written as the value part contains the handle value, when the point/batch point get for update read are used.

Release note

• Change the lock record into put record for the index keys using point/batch point get for update read.

[sre-bot]

Please follow PR Title Format:

• pkg [, pkg2, pkg3]: what's changed

Or if the count of mainly changed packages are more than 3, use

• *: what's changed

[ti-srebot]

No release note, Please follow https://github.com/pingcap/community/blob/master/contributors/release-note-checker.md

[sre-bot]

Please follow PR Title Format:

• pkg [, pkg2, pkg3]: what's changed

Or if the count of mainly changed packages are more than 3, use

• *: what's changed

[ti-srebot]

No release note, Please follow https://github.com/pingcap/community/blob/master/contributors/release-note-checker.md

[cfzjywxk]

/run-all-tests

[cfzjywxk]

/run-all-tests

[cfzjywxk]

As the change may be incorrect, close it.
The value put back is the raw value from kv, it will not be affected by the encoding policy.

[ti-srebot]

cherry pick to release-5.0 in PR #26224

[ti-srebot]

cherry pick to release-5.1 in PR #26225