Adapter for Microsoft SQL Server

[plumsirawit]

I'm trying to implement the Microsoft SQL Server adapter. (which corresponds to this issue)

This is a work in progress. Please feel free to give me some initial reviews and feel free to unassign/kick me in case I'm doing anything wrong 😄

Note that this takes longer than I thought (I thought it would take me at most 2 days, now I think it would take at least one week, or perhaps, more)