Search suggestions queries are cached on the browser side if the only thing that changes in a search suggest source is the query

How to reproduce:

• go to the administration > search > search suggest
• locate the Attachment names source and edit it as follows:
  • set the query to:

    *__INPUT__*
    fq=type:ATTACHMENT
    qf=filename_exact
    

• save
• go to the home of the wiki (without forcing the refresh in the browser)
• make a quick search

Expected result:

• the search results, for attachment names, the results matching the new query are provided
  • in this specific case, a fulltext partial search should be performed

Actual result:

• the returned results are still using the previous search query

This is because the search sources are contained in the javascript for the search suggest, there is a cache invalidation mechanism, but this mechanism does not invalidate the cache when the only change is in the query - it invalidates on name of the suggest, url, highlight and icon, as well as the activation state (see https://github.com/xwiki/xwiki-platform/blob/master/xwiki-platform-core/xwiki-platform-flamingo/xwiki-platform-flamingo-skin/xwiki-platform-flamingo-skin-resources/src/main/resources/flamingo/javascript.vm#L281 ).

As a workaround, changing the name of the source would invalidate the caches on users' browsers.