DataGrid: Make FunctionCompiler extensible

[WolfgangKluge]

Is your feature request related to a problem? Please describe. I have a complex object (EF core with included foreign keys) I want to display (escpecially a part of a 1:n Table). The FunctionCompiler doesn't work well with that (neither Dictionary, dynamic, nor indexer property works). Since the FunctionCompiler is a static class, I cannot extend it the way I need.

Describe the solution you'd like Make the FunctionCompiler a dependency that could be overwritten. That way you can add a compiled function cache, too.

I know I can use the columns without the field - but that has some implications (like sort and filter are not working anymore due to the DataGridColumnInfo inside the DataGridReadDataEventArgs does not contain anything useful to identify the column anymore). That could be workarounded, but it's somewhat harder and not generalizable that easy.

[stsrki]

@David-Moreira, what do you think? It might be worth doing it.

[David-Moreira]

I mean, for us it shouldn't be too hard I guess, we just need to provide it as a "module" that you can just override and make sure to provide your own implementation.