Implement semantic revisioning and release practices for the operator

[jkneubuh]

Implement Semantic Version and a proper release practice for fabric-operator.

• Generate GitHub "release builds" of the operator, associated with release tags
• Write a script, or document the process for turning a release (bumping major, minor, or patch levels)
• publish proper labels for artifact images:

# main line build outputs:
ghcr.io/hyperledger-labs/fabric-operator:latest 

# release line build outputs:
ghcr.io/hyperledger-labs/fabric-operator:v${major}.${minor} 
ghcr.io/hyperledger-labs/fabric-operator:v${major}.${minor}.${patch} 
ghcr.io/hyperledger-labs/fabric-operator:v${major}.${minor}.${patch}-${git-commit-short-hash}