[MAINTENANCE] Improve documentation/usage of integration statuses

[Swiddis]

Is your feature request related to a problem?
Coming from #1530, integration statuses aren't well-documented and also have some standing TODOs in code.

What solution would you like?
This is an issue to hit a couple tweaks:

• Ideally, users should get information on a status if they hover over the badge
• The status type should generally be an enum instead of a string -- refactor
• Find a place to document the integration statuses and what they mean

What alternatives have you considered?
N/A

Do you have any additional context?
N/A

[Swiddis]

From the original plugin design doc, here's the intended meaning of the different statuses:

available The assets are available and functioning.
partially-available Some assets are available, but others may not be. Assets can be opened but may show errors.
unavailable The referenced assets are missing (possibly due to deletion).
corrupted If the integration is somehow in an inconsistent state. This may indicate a bug, but could also happen if a user manually changes some fields that should be constant in normal operation.
unknown IO error while querying for status.