Adds Ubuntu 22_04 image.

This MR adds a new container file based on Ubuntu 22.04. (The old Ubuntu 20.04 will stay available.)

git.rz.tu-bs.de:4567/irmb/virtualfluids/ubuntu22_04

Image contains (amon others):

Software	Version
g++	12
clang	15
Python	3.11
CUDA	12.1.1

Closes #25 (closed) #41 (closed)

Additional changes:

• I commented the unused python unit tests out
• fixed new compiler warnings
• added c-cpp-flylint extension to vscode devcontainer
• added an install cppcheck script to get the newest version
• remved the BUILD_VF_COVERAGE cmake option, as it seems that coverage needs to be enabled with -DCMAKE_BUILD_TYPE=PROFIL according to the newest gcovr docu.