Add MessageGeneration from ros-sharp

[henrikhorluck]

• Somewhat simplified/modernized to .NET 6
• Gives a scaffold to expand for our requirement of binary serialization

Path forward

I would

1. Refactor the code so that it uses an ILogger instead of verbose, probably print warnings with the ILogger (Should check how Support code-generation for messages at build time #57 source-generators expect warnings). Update: should use https://github.com/dotnet/roslyn/blob/main/docs/features/source-generators.cookbook.md#issue-diagnostics, documentation here: https://docs.microsoft.com/en-us/dotnet/api/microsoft.codeanalysis?view=roslyn-dotnet-4.0.1
2. Refactor so that it is more functional aka, there is a function like (msg-text) => C# source code.
3. Verify that the changes I did related to package vs. directory vs. single file are sane, the cli-code of the previous code was a pain to read, and I attempted to reduce code duplication by only having a singel method for code-generation, but it might be that it misses some behaviour we want
4. Add a way to generate and load (and unload??) a class at runtime (see e.g. SO, and How To), this is essential if Analyze is going to be able to change message-definitions when runnning. — otherwise we would have to rebuild Analyze every time, which is not an option.

[henrikhorluck]

1. This has a horrible name, as it generates code, not parse the *.{msg,srv,action}, but that is the authors of ROS#'s fault
2. This can be expanded with a custom interface / method such that code generated support serialization of custom types.

[henrikhorluck]

Also: we are required to add more licensing information as ROS# uses Apache 2.0 https://snyk.io/learn/apache-license/

[Kytzis]

Vil bare forsikre meg med dere som kan litt mer at dette ikke er store problemer før vi merger

[henrikhorluck]

Er sikkert ennå noen bugs i endringene jeg har gjort, men ser ikke at det skal hindre merge fra nåværende tidspunkt

[Kytzis]

Sånn jeg ser det påvirker ikke denne koden det andre for øyeblikket, som gjør at det ikke vil oppstå rare feil med resten av koden dersom det merges