feat: add session and system functions

[Kree0]

Required checklist

• Sample config files updated (config,meta/config and default config)
• If there are user-facing changes, the documentation needs to be updated prior to approving the PR( Link )
• If there are any breaking changes to public APIs, please add the api change label.
• Signed CLA (if not already signed)

Which issue does this PR close?

#1659 #1660 #1661 #1662 #1663
#1664 #1665 #1666 #1667 #1668
#1575 #1753

Rationale for this change

add functions:

select current_role();
select current_user();
select current_tenant();
select current_database();
select @@cluster_name;
select @@server_version;
select @@deployment_mode;
select @@node_id;

fix: root’s role information is no displayed under the default tenant

fix: make the returned message unclear when the username and password do not match

Are there any user-facing changes?

[roseboy-liu]

more test case for your feature

[roseboy-liu]

add role information to cache