feat: Add --no-eval for OCI compatible argument and env var handling, from sylabs 704

[edytuk]

This pulls in sylabs PR

• feat: Add --no-eval for OCI compatible argument and env var handling sylabs/singularity#704
  which fixed
• Compatibility mode to match Docker/OCI arg and env escaping / quoting behaviour sylabs/singularity#487

The original PR description was:

Address sylabs/singularity#487 by adding a --no-eval actions flag, which does the following:

1. Quotes environment variable values in the inject-singularity-env.sh generated script using single quotes to
   ensure the values are not evaluated when the injection script is sourced.
   This behavior applies to existing and newly created images.

2. Uses an alternate path in the generated runscript for images built from OCI sources, that avoids evaluating CMD / ENTRYPOINT parts, and args in the shell.
   This behavior only applies to newly created images, that contain the new form of the generated OCI runscript.

The --no-eval flag is implictly added by the Docker/OCI --compat mode.

Also adds test cases that cover this new functionality, the historic behavior, and general handling of CMD / ENTRYPOINT/ CMD+ENTRYPOINT handling and overrides in Docker/OCI images. This should help us a lot in catching any changes to the 'historic' behaviour, that has been modified inadvertently in the past.

There is no change to the historic behavior of Singularity (run without --no-eval or --compat) at this time. OCI / Docker compatible handling by default may be considered for a future release.

[edytuk]

Changes were made according to your comments

[DrDaveD]

I'm sorry, I asked for the wrong things on my previous review. I didn't realize before that the script file was actually going into the container image. The container image has to stay completely backward compatible, meaning that we only refer to SINGULARITY there, not APPTAINER. So please go ahead and change back all the APPTAINER_OCI_RUN to SINGULARITY_OCI_RUN, and remove the extra case checking $APPTAINER_NO_EVAL. I checked and found out that apptainer is indeed setting SINGULARITY_NO_EVAL with the --no-eval option. It is also setting APPTAINER_NO_EVAL but we can't rely on that because we want containers created by apptainer to still run under singularity.

[edytuk]

I changed back all the APPTAINER_OCI_RUN to SINGULARITY_OCI_RUN, and removed the extra case checking $APPTAINER_NO_EVAL