Implement filtering options for duration type

[kgodey]

Problem

• We need to ensure that records that include columns of duration types support the following filters via API:
  • between {x} and {y}
  • equals {x}
  • does not equal {x}
  • greater than {x}
  • less than {x}
  • greater than or equals {x}
  • less than or equals {x}
  • is empty
  • is not empty
• We need to also ensure that values of the filters don't have to be a number. We should accept natural language like "an hour", or "2 days".
  • We could use something like https://github.com/oleiade/durations or https://github.com/wroberts/pytimeparse

This involves:

• Implementing the filters in the backend
• Updating the /api/v0/databases/<id>/types/ endpoint to store available filters on this type
  • Filter information should include the number of parameters needing to be passed in (e.g. between needs 2 parameters, is empty needs 0)

Additional context

• These filters are the same as those for Number types. We should just reuse those.
  • The only additional thing we need to implement is converting natural language to numbers.
  • Relevant issue: Implement filtering options for Number types. #385
• We're using our fork of sqlalchemy-filters to provide filtering. See: https://github.com/centerofci/sqlalchemy-filters.
• This issue is blocked by implementation of Handle INTERVAL type in the backend #430
• Update filtering issues to cover storing filter/group information in the backend. #557 provides some context on storing filters.

Marking as blocked until #385 and #430 are complete.

[mathemancer]

Similarly to #426, I think there are advantages to using the native PostgreSQL parsing for the human-friendly duration strings, and it's already quite sophisticated and complete.

[kgodey]

Reopening this since it was on @dmos62's standup today.

[dmos62]

Closing. I double checked and the linked PR indeed makes sure that the interval DB type is supported, also the duration UI type is properly declared where appropriate in the filters endpoint. Sorry for the confusion.