Fix wrong date facet values

Problem/Motivation

Currently date-based facets have wrong values, because Swiftype returns the possible date facet filter values as timestamps in milliseconds instead of timestamps in seconds.

Proposed resolution

• Divide returned date facet filter values by 1000 during facet extraction

Remaining tasks

• Provide a patch

User interface changes

n/a

API changes

n/a

Data model changes

n/a

Release notes snippet

n/a