### What?
Aligns types for HiddenField and the WatchCondition component with the
rest of the fields. Since path is required when rendering a Field
component, there is no need to keep it optional in the WatchCondition
component.
### Why?
Hidden fields were requiring the `field` property to be passed, but the
only reason it needed it was to allow the path to fallback to name if
path was not passed. But path is required so there is no need for this
anymore.
This makes using the HiddenField simpler now.
### How?
Adjusts type on the HiddenField and the WatchCondition component.