Support for information_schema database

[BohuTANG]

Summary

Some MySQL driver/GUI(like dbeaver) always access information_schema to fetch some meta information, information_schema tables are actually views, after the view(#4628) checked in, it's time to support the information_schema database, let the GUI easy to connect to Databend.

Tasks:

• Add information_schema database
• Impl some immutable views for information_schema which dbeaver need

[BohuTANG]

@TCeason may have some views information what's dbeaver used.

[TCeason]

Yes, the dbeaver now needs these views in information_schema:

information_schema.COLUMNS
information_schema.TABLES
INFORMATION_SCHEMA.KEYWORDS

And SQL

• show full tables (has already support on local)
• show table status