add support for collections

[rshewitt]

related to 5653

adds support for collections

• this isn't a separate route but a new query parameter similar to current catalog on the index/main search page
• adds a collection card pinned to top of search page
• this expects the parent/child relationship to be established. this doesn't calculate the relationship for dcatus.
• this updates the opensearch mapping object so a complete re-index will be required after merge

update

• example collection on dev. apparently rebuilding the index didn't catch all the documents? i confirmed the dataset(s) were in the catalog read-only db before recreating it but running the sync compare after some time did the charm.

[cmhedrickREI]

Not blocking:
I would like to see maybe a bit of padding or margin to help give space to the stats at the bottom of the card. But that's a personal preference.

This was some great work 👍

[cmhedrickREI]

Thank you for the update 🙌