Problem/Motivation
If an exposed form is used on the same page with facets, it resets facet's URL parameters on each submit.
Proposed resolution
Add "Preserve query parameters from URL" option for the default exposed form plugin.
Remaining tasks
+ write patch
- review
User interface changes
The "Preserve query parameters from URL" setting is added to the "Exposed form style"> "Settings" configuration form.
API changes
None.
Data model changes
Boolean preserve_url_query_parameters is added to views_exposed_form schema.