Allow custom default parameters

[sebasmonia]

I have 0 clue how to implement this (right now my transient definitions are set in stone, basically) but I just found out that dotnet test when using xUnit (standard at work) produces much cleaner output with:

dotnet test ----logger console;verbosity=normal --verbosity quiet

Which means, don't show code warnings and other build output, but then do show the output of the logger.
The way things are now, I have to add the --logger option once per Emacs session, but it would be cool if I can set it up MY as default.

Note that if #1 (State per project) is implemented, and stored between sessions, then this isn't needed anymore.

[sebasmonia]

In f59474d the ability to run a "quick build" for the project of the current buffer/file was added. In that case we also run a bare dotnet build but it would be useful to have the same verbosity and configuration that the "default values" have.