Remove vss-tools submodule and update CI

[SebastianSchildt]

This is a first try to remove vss-tools submodule (which I do believe we should do)

It works "perfectly"... except.... binary exporter because that would need some special treatment as it can not be installed but has some component that needs to be compiled "by hand".

Advantages

• No "arbitrary" version of vss-tools tied via submodule (which may not even be relevant for user who juse us the standard catalgoeu
• would make it easy to adapt to use matrix testing in GH actions (https://docs.github.com/en/actions/writing-workflows/choosing-what-your-workflow-does/running-variations-of-jobs-in-a-workflow) to check several tools versions

Open question: Makefile

Generally I feel the makefile is a bit "anchronistic" and for testing purposes I would move the logic into GH actions. As a "user" I never ever used the Makefile (it seems an extra layer, I would expect: "This is the to tool (vss-tools) and here is how to use it) I do now however it has (had?) fans, so I am also fine with keeping it

Options for binary

• Ignore (as it is now)
• Write some extra script/test to check it
• Somehow make it "easily" available in pip install. However compiling things is not that easy for python packages and we would need to to make sure it at least runs on major platofrms such as arm, amd64, riscv, and than still a windows user might come aorund -> I don't think we should do that.
• Rewrite it in Python ~~(likely equally unrealistic)~~ made an attempt: https://github.com/COVESA/vss-tools/pull/395
• Other options?

Todo

[ ] Update docs [ ] Decide binary [ ] Keep makefile?