Update coding standards and formatting

[lefticus]

• auto-apply clang-format for each commit
• run clang-tidy with each build
• increase warning levels and apply fixes
• hopefully set up an environment where we don't regress in quality settings
• make CMake checks stricter, to make sure proper build environment is set up

[lefticus]

@kbenne I think this is ready for you to look at. Everything builds and runs fine on my side.

[kbenne]

Thank you @lefticus. Wonderful!