Clean up applications

After moving the code that handles sections and tags to `facia`, this PR cleans up the duplication in `applications`.

Apart from mass deletion, there are a few things you should know:

 - `repositories.scala` in `applications` now only contains `ImageQuery`. And missing from it is `Index`, `IndexPage`, and `IndexPagePagination`. This means that `repositories.scala` has been split in half, with most of it moving to `facia` and only a little bit of it left behind.
 - The Tag combiner routes currently do not exist in `facia`, so this removes the **route** and **code** from `applications` and adds the **route** to `facia`.

Before this gets merged `facia` needs to be fully serving fronts, tags, sections and tag combiner pages.

@gklopper