Common PR Workflow

Provide a common PR workflow.
Put as much as reasonable into this central place.

## Current best guess

### Inputs
* Test Results
* Integration parameters (e.g. target version)

### Jobs
* verify some bazel basics (if repo contains bazel)
* sphinx-docs (if repo contains docs)
* linting - if possible
* reference integration test (if repo is a module consumed by reference integration)
* copyright checks
* verify used 3rd party licenses against Apache 2.0 blacklist (Note: tool development not in scope of this issue)