search_get_info() in search.module should include an _alter hook

For Drupal 7 and 8, search_get_info() defines the properties of each module, but there is no way to alter that.

A use case for altering it is to add a conditions callback to node_search_info() when something like facet API is enabled. Currently since there is no conditions callback, it's impossible to search just for items matching a facet filter. Instead, there must always be a non-empty keyword to do a node search.