[security]Introduce row/column level security

[GrapeBaBa]

Security is an important capability for cloud data system. Row level security, Column level security and dynamic data mask are quite useful for data sharing and data governance use case.

I would like to introduce these features to databend. After I read the snowflake document https://docs.snowflake.com/en/user-guide/security-row-intro.html#how-does-a-row-access-policy-work, I think it can be implemented in the current codebase not difficult.

Hope some thoughts and suggestions.

[BohuTANG]

Yes, we(@flaneur2020) are doing some fundamental work on it.
We define out some objects: database, table, share, role etc, and bind some privileges to these objects.
For example:

GRANT SELECT(x,y) ON TABLE db.table TO USER bohu
// SELECT(x,y) is privileges
// db.table is table object
// bohu is user object

RBAC is tracked here: #2815
There is still a lot of work to be done, but it is a very interesting feature!