- Add `IS_RELEASE_BUILD` env variable to indicate release builds
- Set default suffix to RC for releases/v branches
- Set default suffix to DB for develop branch
- Set default suffix to `branch_name` for all other branches
- Add -s flag for manual suffix
- Make sure tags have the right min_version and pre_release_version in their CMakeLists.txt
- Make sure RC builds have the right min_version
- Write variables to GITHUB_ENV if run from workflow
- improve variable names

- `is_release_build` is ignored except if the workflow executes on a `releases/v` branch
- `is_release_build` is false by default and creates RC builds that increment when a new commit is detected
- simplify workflow by using environment variables