tikv: fix primary selection when delete-your-writes

[lysu]

What problem does this PR solve?

Issue Number: close #xxx

Problem Summary:

1. Push down condition check to TiKV for prewrite request #9127 introduce addition useless but sometime wrong DEL mutation for delete-your-writes
2. store: check constraint for "Delete-Your-Writes" records when txn commit #14968 try to remove wrong DEL mutation
3. but wrong DEL mutation can take role as 2pc primary key(or transaction record) to works well in some situation, but store: check constraint for "Delete-Your-Writes" records when txn commit #14968 remove it will cause prewrite locks's primary property point to a unwriten primary key
4. any read-write request see those uncommited lock with wrong primary key value will treat them belong rollbacked transaction, but real transaction invoker maybe think transaction has be success.

so it will cause read/write inconsistent result when meet lock that point to a primary key has be insert/delete in own txn.

https://github.com/pingcap/tidb/pull/18244/files#diff-d11e207d2529a00e79d72b84ae5172caR722 will fail and read nothing to reproduce it in 2pc test case level.

What is changed and how it works?

What's Changed, How it Works:

choose first key didn't be delete by itself as primary key.

Related changes

• Need to cherry-pick to the release branch 3.0

Check List

Tests

• Unit test

Side effects

• n/a

Release note

• Fix read/write inconsistent result when meet lock that point to a primary key has be insert/delete in own txn

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This change is 

[codecov]

Codecov Report

Merging #18244 into master will decrease coverage by 0.1122%.
The diff coverage is 100.0000%.

@@               Coverage Diff                @@
##             master     #18244        +/-   ##
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- Coverage   79.5531%   79.4408%   -0.1123%     
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  Files           535        535                
  Lines        144443     143907       -536     
================================================
- Hits         114909     114321       -588     
- Misses        20268      20319        +51     
- Partials       9266       9267         +1     

[lysu]

/run-all-tests

[jackysp]

LGTM

[ti-srebot]

@jackysp,Thanks for you review.

[bobotu]

LGTM

[ti-srebot]

@bobotu,Thanks for you review.

[coocood]

LGTM

[ti-srebot]

@coocood,Thanks for you review.

[ti-srebot]

cherry pick to release-3.0 in PR #18248

[ti-srebot]

cherry pick to release-3.1 in PR #18249

[ti-srebot]

cherry pick to release-4.0 in PR #18250