SQL Server: Handle non-UTC servers

[NickCraver]

Currently several assumptions are made about UTC time, while I think all servers should be running in UTC time that's obviously not reality and we need to handle it. Some PRs have tried this in a very heavy way - but I think we need something a bit simpler, possibly in a Dapper type converter on those types? Or a post-processor for server time offsets via an attribute on the properties for those DMV columns?

This issue is for tracking. Relevant past PRs: #42 and #225