[YSQL] Master UI: Users should be able to find the tablegroup ID from the tablegroup name

[lnguyen-yugabyte]

Jira Link: DB-988

Description

Currently the tablegroup name is displayed as following on the UI / queried via yb-admin: [000033e1000030008000000000004101.tablegroup.parent.tablename]

Instead, we should be able to show the tablegroup name as created by user.

(Note that currently it's possible to look up the tablegroup ID from name in an indirect way: look up the YSQL OID associated with the table, and look up on the UI the tablegroup ID with the given OID. However we should not have to resort through YSQL OID for this.)

[frozenspider]

Technical details/implementation idea:
ID 000033e1000030008000000000004101 can be parsed to get database OID and table OID (which is actually a tablegroup OID). We can then do a lookup in pg_yb_tablegroup table by OID to get the actual group name.

[tverona1]

Closing this as a duplicate of #5086. We won't show tablegroup name as part of colocation GA.