### Does this PR have any customer impact?
Yes
### Type (Feature, Refactoring, Bugfix, DevOps, Testing, Perf, etc)
Feature
### Does it involve schema level changes? (Table, Column, Index, UDF, etc level changes)
No
### Are you introducing any new config? If yes, do you have tests with and without them being set?
No
### ChangeLog (Refer [Template](../oss/CHANGELOG.md))
### Description
Move pg_documentdb_extended_rum to the top level folder from the internal folder since documentdb (tests and product) now has a dependency on it.
pg_documentdb_extended_rum is a fork of the RUM Extension that provides extensions that were needed for documentdb. This includes the ability to push down order by and group by to the index; The ability to do index only scans; improvements on vacuum and handling of page splits; index scan improvements while retaining the original inverted index for text search capabilities that the RUM index had.
Signed-off-by: Shuai Tian <shuaitian@microsoft.com>
