Implement filtering options for the URI type

[kgodey]

Problem

We need to ensure that records that include columns of the custom URI type support the following filters via API:

• contains {x}
• does not contain {x}
• is {x}
• is not {x}
• is empty
• is not empty
• host contains {x}
• host does not contain {x}
• scheme is [select from list of choices of valid schemes]
• scheme is not [select from list of choices of valid schemes]

The ones in bold are unique to the URI type.

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. is needs 1 parameter, is empty needs 0)
  • Filter information should also include the list of valid choices for the filter (e.g. scheme filters)

Additional context

• We're using our fork of sqlalchemy-filters to provide filtering. See: https://github.com/centerofci/sqlalchemy-filters.
• Blocked by Create URI custom type and handle it in the backend. #412
• Update filtering issues to cover storing filter/group information in the backend. #557 provides some context on storing filters.

[dmos62]

... [select from list of choices of valid schemes]

The set of valid schemes is unknown. There's a set of "official" URI schemes, but a scheme can be unofficial too. I think we'll have to ask the user to input a scheme to filter against himself.