Feature/v0.10 sql ddl

[Yaiba]

This pr adds new DDLs:

• create table
• alter table
• create index
• drop index

[Yaiba]

To deal with new DDL, I create ParseDDL and WriteDDL for now so I don't break the downstream analyzer/planner, also allow me to write tests.

Also add some basic validations on create table

[Yaiba]

OK Just add Drop table statement, also address feedback on ParseDDL function.