### _Why are the changes needed?_
Kyuubi supports GROUP engine share level, currently, it just simply delegates the group provider to Hadoop UserGroupInformation, which is not flexible enough for users who want to use other group mapping mechanisms, e.g. LDAP, JDBC.
This PR supplies a pluggable plugin interface `GroupProvider` and provides a built-in `HadoopGroupProvider` which has the same behavior w/ the current implementation.
W/ this change, users can easily implement `LDAPGroupProvider`, `JDBCGroupProvider`, `FileGroupProvider`, `CustomGroupProvider`, etc. then the GROUP engine share level will be more powerful and flexible.
The alternative option is to guide users to learn and extend the Hadoop group mapping system[1].
[1] https://hadoop.apache.org/docs/stable/hadoop-project-dist/hadoop-common/GroupsMapping.html
### _How was this patch tested?_
- [x] Add some test cases that check the changes thoroughly including negative and positive cases if possible
- [ ] Add screenshots for manual tests if appropriate
- [x] [Run test](https://kyuubi.apache.org/docs/latest/develop_tools/testing.html#running-tests) locally before make a pull request
Closes#3897 from pan3793/group.
Closes#3897
b100348e [Cheng Pan] nit
3cce6451 [Cheng Pan] Supplying plugable GroupProvider
Authored-by: Cheng Pan <chengpan@apache.org>
Signed-off-by: Cheng Pan <chengpan@apache.org>
4730d11ad7