Summary:
Removing unneccessary sharedlock in DeleteOrHideTabletsAndSendRequests that was causing a potential
deadlock.

Also adding in test for testing #22608 which is how this bug was discovered
Jira: DB-11526

Test Plan: ybd --cxx-test xcluster-tablet-split-itest --gtest_filter "CdcTabletSplitThreeMastersITest.TestRaceAfterHidingAndRetainingTablet"

Reviewers: xCluster, hsunder, skumar, vkushwaha

Reviewed By: hsunder

Subscribers: ybase

Differential Revision: https://phorge.dev.yugabyte.com/D35457