Removing ORM and moving from Gorm to vanilla sql

[mabdh]

Summary
For some basic CRUD, ORM is helpful and help us faster in development. However, in our current state of Guardian, there are some cases when using gorm as an ORM will overcomplicate the query since we need more advanced query.

Proposed solution
We can remove the ORM to get more flexibility to build a query and use query builder (goqu, squirrel, etc) instead to help it.

For db package, we can use the one in https://github.com/odpf/salt