Add date filtering to image search

[jtweed]

Background

To help users find images from a certain period of time, we want to add date filtering and sorting to image search. This should filter images based on the dates of the source work.

Approach

• [x] Add date range filtering to the images API. This should match the date range filtering in the works API, with the parameters source.production.dates.from and source.production.dates.to.
• [x] Add a source.production.dates aggregation to the images API.
• [x] Add a sort option production.dates. (https://github.com/wellcomecollection/catalogue-api/pull/648)
• [x] Make sure the new API additions are added to the API documentation. (https://github.com/wellcomecollection/developers.wellcomecollection.org/pull/20)
• [x] Add a Dates filter to image search between Licenses and Types/Techniques (we will monitor usage to determine final position). (https://github.com/wellcomecollection/wellcomecollection.org/pull/9952) + correction (https://github.com/wellcomecollection/wellcomecollection.org/pull/9961)
• [x] Add sorting to image search, with the options "Relevance", "Oldest to newest", "Newest to oldest". (https://github.com/wellcomecollection/wellcomecollection.org/pull/9997)
• [ ] Make sure that the new filter is tracked in the search metrics and visible on the dashboard.

[alexwlchan]

Moving back to "Next" for somebody to pick up adding these filters to the front-end.

[georgiaewhitney]

Moved back to in progress for final step