Change outer git hash to pipeline ID

This is for discoverability on merge requests, where the commit does not persist after the pipeline has run.

Before: Merge request CI generates a commit hash for 'if this were to be merged now' and that commit hash is placed on the body. Once the pipeline has run, the temporary commit hash is visible in the MR. However when the next pipeline runs the temporary commit is no-longer discoverable. This makes it impossible to use the hash on a main body that was created by an intermediate MR pipeline to identify the source. (for the pipeline of an actual merge the commit hash is in the line of commits on the repository and is visible.)

After: The outer tag position, where the version is placed on releases, has the pipeline number. The pipeline is sequentially numbered so is relatively easy to trace back in the Build-Pipelines list. The full number is 10 digits, which does not really fit, but the first and last digits are less important for locating the correct pipeline.

!528 (merged) was merged in here. There are further related discussion threads on that MR.