feature: support oracle and postgresql multi primary key

[tuwenlin]

• I have registered the PR changes.

Ⅰ. Describe what this PR did

support oracle and postgresql multi primary key
oracle和postgersql支持复合主键，请告知测试用例如何提供

Ⅱ. Does this pull request fix one issue?

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

Ⅳ. Describe how to verify it

Ⅴ. Special notes for reviews

[funky-eyes]

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33774360

[tuwenlin]

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好的，稍后会加进去

[tuwenlin]

这是我们贡献者的钉钉群,你方便加一下吗,这样也方便交流 33774360

oracle和postgresql测试项目https://github.com/tuwenlin/seata-multi-pk-demo.git

[codecov-commenter]

Codecov Report

Merging #4457 (234a24c) into develop (a05e5d9) will decrease coverage by 0.00%.
The diff coverage is 41.86%.

@@              Coverage Diff              @@
##             develop    #4457      +/-   ##
=============================================
- Coverage      49.45%   49.44%   -0.01%     
- Complexity      4071     4077       +6     
=============================================
  Files            732      732              
  Lines          25521    25517       -4     
  Branches        3153     3154       +1     
=============================================
- Hits           12621    12618       -3     
- Misses         11554    11564      +10     
+ Partials        1346     1335      -11     

Impacted Files	Coverage Δ
...ta/rm/datasource/exec/AbstractDMLBaseExecutor.java	52.94% <ø> (-1.78%)	⬇️
.../rm/datasource/exec/mysql/MySQLInsertExecutor.java	69.14% <ø> (ø)
...source/exec/mysql/MySQLInsertOrUpdateExecutor.java	31.07% <0.00%> (ø)
...boot/autoconfigure/properties/SeataProperties.java	35.55% <0.00%> (-5.48%)	⬇️
...ing/boot/autoconfigure/SeataAutoConfiguration.java	0.00% <0.00%> (ø)
...ta/spring/annotation/GlobalTransactionScanner.java	30.65% <0.00%> (ø)
...o/seata/rm/datasource/exec/BaseInsertExecutor.java	72.19% <50.00%> (+1.06%)	⬆️
...urce/exec/postgresql/PostgresqlInsertExecutor.java	66.66% <57.14%> (+22.91%)	⬆️
...m/datasource/exec/oracle/OracleInsertExecutor.java	73.68% <69.23%> (+11.18%)	⬆️
...o/seata/server/coordinator/DefaultCoordinator.java	47.95% <0.00%> (-6.15%)	⬇️
... and 14 more

[tuwenlin]

这是我们贡献者的钉钉群,你方便加一下吗,这样也方便交流 33774360

oracle和postgresql测试项目https://github.com/tuwenlin/seata-multi-pk-demo.git

简单说一下实现思路：
首先，多主键只会在insert时用到，因为回滚要根据主键delete数据
Oracle主键分为四种类型处理：1.写在Insert语句中的主键.2.序列3.函数.4.NULL
1.写在Insert语句中的主键，通过解析sql获取，同时获取其他主键的类型
2.序列，通过getPkValuesBySequence方法获取，方法新增了参数pkKey,为主键的列名，先通过getGeneratedKeys方法中获取，这个方法也增加了参数pkKey，为什么要这么做，因为原getGeneratedKeys方法中，调用了targetStatement.getGeneratedKeys()，并默认获取了ResultSet中第一个作为主键，应该根据列名去获取主键，所以这两个方法增加了pkKey参数，如果无法通过targetStatement.getGeneratedKeys()获取主键value，执行对应的Sequence，去获取当前序列的值；
3.函数，函数类型的主键只能通过getGeneratedKeys方法去获取主键的value，获取不到value，则抛出不支持异常
4.NULL，NULL值的主键value也通过targetStatement.getGeneratedKeys()获取
PGSQL主键没有NULL值，有Default值，其余三种和Oracle获取value一样
PGSQL的Default类型通过getPkValuesByDefault方法获取，先通过metadata获取默认值，再根据默认值，按照3种类型再去解析

最终，多主键最多允许一个为NULL，不允许出现函数（这块跟上面有冲突，抽空验证后再觉得是否要去掉上述函数类型分支）