Add support for Microsoft SQL Server

[iaincollins]

Testing out the new Microsoft SQL Server support added by @D10221

• I'm happy this seems to work well and that it is ready for release.
• I've tested positive and negative flows with a range of providers, including email.
• The only changes to the original excellent Pull Request have been to the index (to allow multiple UNIQUE NULL values on email address, which is behaviour SQL Server handles slightly differently by design) and minor edits to documentation.

I propose we release this as v3.1 - along with the Basecamp provider PR in #511 and the support for entity hot reloading in #488, unless there are any objections or any other features or changes people would like to see make the cut?

Thanks again @D10221!

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[D10221]

As per Ms docs, snake_case should be the choice.
Another case for the snake-case, no pun intended, is it's case-insentive nature. Like css, urls. or cross-plaform file naming conventions

But I know by experience that is very common to use TitleCase, due it's strong connection to the .Net framework , c#, entity-framework, LinkToSql, Dapper, etc... due to tie to the POCOS (plain c# objects) m, Dtos or whatever you want to call them :).

Nevertheless I've seen Hungarian notation like naming everywhere too :(

Personally, I'll prefer names that can be mapped straight to the naming convention of language you are working on, just in case you need to 'raw query'.
As an example in Js I'll preffer camelCase, but I'm not offended snake_case ... I rather like it :), I feel is very neutral.

And again that might not be a problem with next-auth, or typeorm, as there is no need to have the models named exactly as they were typed on the database (correct me if wrong).
But with other mapping libraries like the plain 'mssql' or 'tedious' libs you get exactly what you typed on the queries and may complicate mappings if you have to share the database with those libs, or 'raw quieries' :)

IMMO as far you can change it to suit you needs it's all good. :)

... sorry it got a bit long

[iaincollins]

@D10221 Thank you for the quick response, that's a really complete answer and I appreciate it!

I'm not familiar with mssql culture / conventions so wanted to avoid us doing something unconventional by default.