Added documentation for Locale Switcher

The Locale Switcher provides some configuration flags that have been documented in the Studio developer manual.

(CMS-23484)

Optimized Dashboard Requests

Fixed issue that the initial dashboard loading executed Solr requests twice for every search widget.

(CMS-23468)

Added flag to disable library auto search

The configuration flag CollectionViewBase.GLOBAL_SEARCH_FALLBACK_ENABLED can be set to false if the extended search for empty results in the library should be disabled.

(CMS-23181)

Removed Taxonomy User Check

The check wasn't anymore but there were remaing code snippets and also some documentation which has not been removed properly.

(CMS-23039)