Allow search results to not fail when searching namespaced tags without namespaces.

[chaskayote]

Is your feature request related to a problem? Please describe.
Most people come to booru site and assume they can just type in the name of an oc or artist. For instance, search for dripponi and get results. As it is now, you have to type in artist:dripponi. (I do love namespaces and they're amazing but this was more for user friendly.

Describe the solution you'd like
Searching for artist:dripponi and dripponi both bring up the same search results.

Describe alternatives you've considered
Dealing with it. Potential issues is if an artist name matches a general tag with no namespace. It would be cool is if it could display both tags and then you could click one to drill down.

Additional context
I've tried experimenting with this with some edits to the code. I tried editing line 159 of search_index.ex to the following:

        name: image.tags |> Enum.flat_map(&([&1] ++ &1.aliases)) |> Enum.map(& &1.name),
        name_in_namespace:
          image.tags |> Enum.flat_map(&([&1] ++ &1.aliases)) |> Enum.map(& &1.name_in_namespace)

and changing line 96 of query.ex to
default_field: {"namespaced_tags.name_in_namespace", :term},

The problem I'm having is now searching the old way fails and when "dripponi" comes up, it doesn't show the tag details just the images.