Summary:
When deleting a transaction table, the master leader fans out the new transaction tables version to all tablet servers. There is no liveness check on tablet servers, and this operation must succeed for the transaction table to be deleted. Therefore if a tablet server has been taken down it is impossible to delete a transaction table without clearing master leader knowledge of the dead tablet server.

This diff changes the fan out logic to only contact live tablet servers, using the same liveness condition as the load balancer does.
Jira: DB-18831

Test Plan:
```
./yb_build.sh release --cxx-test delete_table-test --cxx-test-filter-re delete_table-test --gtest_filter 'DeleteTableTest.DeleteTransactionTable'
```

Reviewers: asrivastava

Reviewed By: asrivastava

Subscribers: esheng, ybase, rthallam

Differential Revision: https://phorge.dev.yugabyte.com/D48126