Implement semantic revisioning and release practices for the operator

Implement [Semantic Version](https://semver.org) 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}
```

Start by locating the operator's current build, image-publishing, and release configuration; the issue names no files or tests. Establish how tags and GitHub release builds should be produced, then verify that main-line and versioned image labels match the listed formats and that the documented release process covers major, minor, and patch bumps.

Written by the indexing model from the issue text.