Initialize the repository

[mpostol]

All related work to prepare the repository for further development.

Follow community recommended standards
Blocker for: mpostol/OPC-UA-OOI#409
Scope:

• .gitignore
• social preview
• License
• Code of conduct
• Contributing or use default one
• sponsor button
• add nugets
• add common resources and t4 definitions
• fix compiler errors
• fix Unit tests
• Make release

[mpostol]

Make release moved to separate issue #3