optimize: When the number of primary keys exceeds 1000, use union to concatenate the SQL #6957

[remind]

…oncatenate the SQL (#6957)

• I have registered the PR changes.

Ⅰ. Describe what this PR did

When the number of primary keys exceeds 1000, use union to concatenate the SQL

Ⅱ. Does this pull request fix one issue?

fixes #6957

Ⅲ. Why don't you add test cases (unit test/integration test)?

Ⅳ. Describe how to verify it

sql生成有测试用例：
io.seata.rm.datasource.SqlGenerateUtilsTest
此测试类之前已经存在，此次在此基础上进行了修改

其它受影响的地方依赖其它已有测试用例，由于该问题的触发场景比较极端，必须要超过1000个主键，并且该1000的配置是private的，有部分场景没看到之前有编写超过1000时的测试用例，本地通过修改配置值进行了单元测试，不确定集成测试是否有此场景的测试。

Ⅴ. Special notes for reviews

1、io.seata.rm.datasource.undo.AbstractUndoExecutor#queryCurrentRecords 该方法是使用了For Update，之前是一条sql一次性执行完，当主键数量超过1000时现在会拆分成多条sql循环执行，每条执行会有间隔，如果有同样的数据重复处理，并且是不同事务的，可能会导致死锁。

2、由于sql采用了union拼接，影响到了SQLSelectQueryBlock的获取，因此在*SelectForUpdateRecognizer此种类中，如io.seata.sqlparser.druid.mysql.MySQLSelectForUpdateRecognizer#getSelect，修改了获取方式，是否有可能造成影响。

[codecov]

Codecov Report

Attention: Patch coverage is 94.33962% with 3 lines in your changes missing coverage. Please review.

Project coverage is 52.65%. Comparing base (26950b6) to head (bd674c0).
Report is 2 commits behind head on 2.x.

Files with missing lines	Patch %	Lines
...qlparser/druid/dm/DmSelectForUpdateRecognizer.java	0.00%	1 Missing ⚠️
.../druid/oracle/OracleSelectForUpdateRecognizer.java	0.00%	1 Missing ⚠️
...ostgresql/PostgresqlSelectForUpdateRecognizer.java	0.00%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##                2.x    #7012      +/-   ##
============================================
- Coverage     52.66%   52.65%   -0.01%     
- Complexity     6643     6663      +20     
============================================
  Files          1126     1129       +3     
  Lines         40142    40168      +26     
  Branches       4707     4708       +1     
============================================
+ Hits          21139    21151      +12     
- Misses        16990    17000      +10     
- Partials       2013     2017       +4     

Files with missing lines	Coverage Δ
...g/apache/seata/rm/datasource/SqlGenerateUtils.java	96.22% <100.00%> (+1.10%)	⬆️
.../rm/datasource/exec/BaseTransactionalExecutor.java	74.12% <100.00%> (+0.12%)	⬆️
.../seata/rm/datasource/exec/MultiUpdateExecutor.java	80.00% <100.00%> (-0.27%)	⬇️
...pache/seata/rm/datasource/exec/UpdateExecutor.java	83.33% <100.00%> (-0.76%)	⬇️
...datasource/exec/mysql/MySQLUpdateJoinExecutor.java	77.56% <100.00%> (-0.70%)	⬇️
...seata/rm/datasource/undo/AbstractUndoExecutor.java	67.53% <100.00%> (+0.86%)	⬆️
...er/druid/mysql/MySQLSelectForUpdateRecognizer.java	78.37% <100.00%> (ø)
...id/sqlserver/SqlServerOperateRecognizerHolder.java	68.42% <100.00%> (ø)
...qlparser/druid/dm/DmSelectForUpdateRecognizer.java	0.00% <0.00%> (ø)
.../druid/oracle/OracleSelectForUpdateRecognizer.java	11.42% <0.00%> (ø)
... and 1 more

... and 8 files with indirect coverage changes

[funky-eyes]

LGTM