- Adds setting to enable or disable processing of HTTP headers related to IP forwarding.
- Increases test coverage.

- Resolves VUFIND-1409.

The use of $$ confuses the static code analysis and provides false positive warnings in this function.

- Better support of single sign-on
- Added missing translation call

- Use more inclusive language.

This cleans up and compresses the result by putting all the small scripts to a single block.

Switches to a JS cookie library that supports the SameSite attribute.

- Use flex to simplify result thumbnail styling, prevent oversampling.
- Add missing alt tags to AJAX-loaded covers.

- Add ability to use direct URLs from cover services in UI
- Add ObalkyKnih.cz covers provider
- Add option to load cover information via AJAX (important for performance when working with direct URLs from cover services)

- Also tweak comments a bit.