[FEATURE] explicit version or machine-readable date for standard to allow referencing from other places

[GraemeSutherlandHO]

What is the feature or enhancement you are suggesting?
Add a version or date to a standard that can reference a particular version of it.

What would be the benefit of doing this?
When referencing a standard (or conforming to it), what happens if it is revised. This means that somebody could have been compliant and is then not. Arguments will follow. Think we need to be able to refer to a standard's explicit version externally (a hash, a version or tag, that is exposed). Also need to be able to retrieve older versions when needed to refer.

Additional information
See also #315 which would require ability to reference a particular version.

Please confirm the below

• I have checked through the issues on the repository and this has not already been suggested

[edhamiltonHO]

Initial suggestion for an MVP is to
In layout for a standard
Display a list of previous iterations of that standard (linked to commit hash for that md file)
Potentially also include a link to the full history in Github for that md file

[jeff-horton-ho-sas]

To add a permalink to the current snapshot in GH we need the commit SHA when building the static site. To pass this in to the docker build we need to modify the shared SAS github actions as follows:

• Get the sha from a build arg in the Dockerfile
• Adding build-args input and build-args: ${{ inputs.build-args }} to the sas action https://github.com/UKHomeOffice/sas-github-workflows/blob/main/.github/actions/docker-publish/action.yml#L49-L58
• Adding same to the sas workflow https://github.com/UKHomeOffice/sas-github-workflows/blob/main/.github/workflows/publish-docker.yml#L51-L60
• Add sha to workflow call in this repo https://github.com/UKHomeOffice/engineering-guidance-and-standards/blob/main/.github/workflows/build-and-publish-docker.yml

[jeff-horton-ho-sas]

Paused pending switch to core-cloud which will remove the issue of building the SHA into the docker image.