Allow including Main.Search and Main.SolrSearch in other pages

Right now there are two problems if you try to use {{include reference="Main.Search"/}}:

• It'll display not only the form but also the search results on the including page. IMO it should only display the form.
• It'll prevent the page from being editable.

Note that for the first problem the user could write instead:

{{velocity}}
{{include reference="Main.SolrSearchConfig" /}}

{{include reference="Main.SolrSearchMacros" /}}

#displaySearchUI()
{{/velocity}}

However that's more technical and we know users will try to include "Main.Search" anwyay, see XWIKI-14388