MGNLUI-8306

Also integrate feedback on existing search docs from LD on 18/03:

• No suggestions in Find bar anymore
• Search starts from 3 characters
• Remove In-chooser searches section, it's overkill and will change 
• Thumbnail view of Assets app has been removed (make sure this goes into RN, need ticket number). Previews and mini thumbnail in tree view remain.
• Merge user-based ranking section into the explanation of search, applies to both find bar and in app search. Should look like normal behavior not a special "thing". Filtering- merge two types.
• Remove all ref to image rec such as "If you use the [Magnolia Image Recognition module](https://docs.magnolia-cms.com/product-docs/6.2/Features/Image-recognition/), all automatically generated tags applied to your assets are available." from the search pages, as it's irrelevant.
• New page - content app search page for in app search that highlights the defaults, you can configure filters and sorting.** Decided on a single page about seaching in mgnl
• Remove sorting page

TBC - Are Find bar commands documented here: https://preview-magnolia-63.netlify.app/product-docs/6.3/authoring/search/searching-for-content still valid?