Add the ability to use NpgSql (Postgres) db provider or SqlServer

[Kronos11]

Adds in functionality for #137

What this PR does / why we need it:

This PR adds Npgsql as a separate database provider by creating a separate project for NpgSql and SqlServer

TODO:

• [x] Add in Migrations for NpgSql
• [ ] Update documentation and samples
• [ ] Unit Tests

• [ ] Functional Tests

  Please make sure you've completed the relevant tasks for this PR, out of the following list:

  • [x] Code compiles correctly
  • [ ] Created/updated tests
  • [x] Unit tests passing
  • [ ] End-to-end tests passing
  • [ ] Add documentation
  • [ ] Provided sample for the feature

[Kronos11]

I think I can actually get rid of the two separate projects and have a 'Storage' project which has the factory as well as the migrations (only thing is the Deployments table has a ByDefault column which npgsql will set the default value to false and sqlserver to 0)

[Kronos11]

Closing this, will re-open with a cleaner request.