Incorporate install profile work

[rosiel]

Having merged:

• Bd d9 updates islandora_base_theme#2
• Bd d9 update islandora_starter_theme#4
• Drupal 9 Update for December 2021 Sprint islandora_install_profile_demo#5

We are hoping to merge the Install Profile work into the main sandbox branch, then update and merge Islandora-Devops/isle-dc#160.

[rosiel]

The difference here is too much for git merge. We want to effectively stomp over the old main branch.

[rosiel]

If you are confident that this belongs on the main branch, here is a proposal to:

• avoid the stuff in main being merged into this work (even if we resolve the merge conflicts, we get a bunch of extra stuff!)
• preserve git history (including everything in main)

I'll make a PR against main that sets its codebase back to the parent commit where this branched off from. Then this should merge cleanly.

Credit to @alxp for the clever idea

[rosiel]

If we merge #6 this one can be merged.