This is an automated cherry-pick of #17625

What is changed and how it works?

Issue Number: Close #12410 and #17602.

What's Changed:

As issues #12410 and #17602 shows, the original design of CmdEpochChecker allows the BatchSplit or Split proposals even though the last TransferLeader is still on-going, making the newly created region cannot campaign leader immediately. The root cause of these issues is that TransferLeader does not be recorded into the proposal queue in CmdEpochChecker as it will not change the conf_ver, if the proposal queue has no conflicts admin commands.
And these issues will damage the stability of TiKV, returning 9005 errors to the Client who wanna access the relative data.

So, to tackle these issues, this pr make the campaign of the newly splitted regions triggered in time, when the leadership of the parent region is stable after on_role_changed. And the newly added progress can be reviewed from the following diagram on step 6.

This pr make the `campaign` of the newly splitted regions triggered in time, when the leadership of the parent region is stable after `on_role_changed`.

Related changes

• PR to update pingcap/docs/pingcap/docs-cn:
• Need to cherry-pick to the release branch

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
• No code

Side effects

• Performance regression: Consumes more CPU
• Performance regression: Consumes more Memory
• Breaking backward compatibility

Release note

This pr introduces an supplementary rule, making `TransferLeader` mutually exclusive with other commands 
which will change the `conf_ver`, for checking the execution validity.