Implement filtering options for the email type

[kgodey]

Problem

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

• contains {x}
• does not contain {x}
• is {x}
• is not {x}
• is empty
• is not empty
• domain contains {x}
• domain does not contain {x}
• domain is {x}
• domain is not {x}

The ones in bold are unique to the email 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)

Additional context

• We're using our fork of sqlalchemy-filters to provide filtering. See: https://github.com/centerofci/sqlalchemy-filters.
• Update filtering issues to cover storing filter/group information in the backend. #557 provides some context on storing filters.