Allow year and month to be hidden when displaying EDTF dates

[seth-shaw-unlv]

GitHub Issue: N/A

What does this Pull Request do?

Allow year and month to be hidden when displaying EDTF dates. Taken from Born-Digital's updates to carapace. They used it for the newspaper view; this PR pulls in these nice additions for those not using carapace.

What's new?

A in-depth description of the changes made by this PR. Technical details and possible side effects.

• Added 'no value' options for month.
• Added year formatting options
• Does this change require documentation to be updated? No.
• Does this change add any new dependencies? No.
• Does this change require any other modifications to be made to the repository (i.e. Regeneration activity, etc.)? No.
• Could this change impact execution of existing code? No.

How should this be tested?

• Apply the PR
• Use the EDTF date formatter settings to hide a month and/or year
• Ensure nothing blows up on us.

Interested parties

@Islandora/8-x-committers and @noahwsmith

[noahwsmith]

cc @dannylamb for comment and code review. Seth and I talked about this last week and I suggested he extract this from our install-profile if it seemed more broadly usable 👍