[IMPLEMENT] Upgrade to Umbraco v10 and Net 6

[NikRimington]

• [IMPLEMENT] Update to Net6
• [AMEND] Replace use of WebRequest with HTTPClient
• [IMPLEMENT] SQLite Support for Umbraco v10

Notes:

• SQLite support required a messy amend as SQLite doesn't support Select Top() so you have to use Limit, but SQL doesn't support limit.
• Removal of .ToString() when passing in the Object Type as SQLite doesn't work with it, but SQL and SQLite both work without.

[enkelmedia]

Thanks for the PR!

I fiddled around with the branches and your contribution is now part of the official 10.0.0-release.

https://github.com/enkelmedia/TheDashboard

[enkelmedia]

Pushed to Nuget =D