Fix MilCodeGen

[ThomasGoulet73]

The goal of this issue is to track the work of fixing MilCodeGen and be able to run MilCodeGen when we need to modify generated code.

The necessary steps for this are:

1. Fix the build of MilCodeGen and Csp to be able to run it: dotnet/wpf#10417
2. Sync the code generators to the generated code since the generated code was modified manually instead of running MilCodegen: Not done yet
3. Update the generated code by running MilCodeGen: Not done yet

Followup work once the previous steps are done include:

• Update MilCodeGen to .Net Core. See https://github.com/dotnet/wpf/pull/10417#discussion_r1947354252
• Validate unused generators/dead code and check whether we should remove it or enable it. See https://github.com/dotnet/wpf/pull/10417#discussion_r1947365852 and https://github.com/dotnet/wpf/pull/10431#discussion_r1947490249
• Transition MilCodeGen to a Roslyn-based code generator and remove Csp. (Maybe in the future)