Replace sqlite-net-pcl with something else

[COM8]

Since sqlite-net-pcl is by far not well enough maintained we should switch away from it.

An alternative would be to use Entity Framework Core.
There is just one problem with it:

• It requires 16299 as min SDK version but phones only support 15063 as min SDK. So we would have to use a version < 2.1.

[COM8]

SQLitePCL.raw and SQLitePCL.pretty look like valid options.

[COM8]

SQLitePCL.raw requires the following NuGet packages:

• SQLitePCLRaw.core
• SQLitePCLRaw.lib.e_sqlite3.v140
• SQLitePCLRaw.provider.e_sqlite3.uwp10