Add Gitlab CI linter jobs

See #21

Csharp linter (by @yc6371 )

1. Use dotnet6 sdk as it’s LTS (Long Term Support) version
2. Use MSFT built-in code quality analysis and style checking performed on build (see default rules. Configuration in .editorconfig)
3. create temp.csproj for build purpose

Python linter (by @yc6371 )

1. Use pycodestyle for format conforming to PEP8 guide (Configuration in setup.cfg)
2. Use pylint for code quality analysis (Configuration in .pylintrc)

• split python linter into 2 parts: one for formatting, another for code quality analysis

Javascript linter (by @mohanna.radakrishna )

1. Use ESlint for code style analysis to conform Airbnb style guide (Configuration in .eslintrc)
2. Edit package.json for build purpose

C++ linter (by @mohanna.radakrishna )

1. Use CPPlint for code style and code quality analysis to conform Google C++ Style Guide (Configuration in CPPLINT.cfg)

Bash linter (by @mohanna.radakrishna )

1. Use Shellcheck for code style and code quality analysis to conform Google Shell Style Guide guide (Configuration in .shellcheckrc)