Improve build and infra scripts

[PokhodenkoSA]

A lot of improvements:

• .gitattributes for fixing Windows/Linux EOL - safely pass code from Windows to WSL
• Apply flake8, config and skips in .flake8, fixed a lot of warnings
• Add recommended VSCode extensions .vscode/settings.json
• Added whitespace fixers, isort, flake8 and shellcheck in pre-commit
• Added buid and development environments for conda (build-environment.yml amd environment.yml)
• Fixed conda sctipts build.sh and run_test.sh using shellcheck
• Improved processing for NUMBA_DPPY_LLVM_SPIRV_ROOT in run_test.sh
• Configured isort to not conflict with black
• And more...