Add `interval` to the `capture` create/edits

[travjenkins]

We need to add the interval property on the process for creating and editing Captures. This will be added in a similar space as backfill' andauto discover` stuff. This field should really only be shown for certain connectors as it does not always make sense.

Design

The input should end up something like this:

Spec

[kiahna-tucker]

The column, default_capture_interval, on the connector_tags table dictates whether the field should appear and what the default value should be.