tidy up our angular DatabaseEdit controller and remove statically coded values from frontend and pull it via form_input endpoint.

move /frontend_client -> /resources/frontend_client to make sure the static resources are bundled in our jar files.
small updates to main routes.clj file to make static asset serving from "resources" instead of "files", which allows for serving out of jars.

because of copypasta. 'Add Database' now allows you to specify the type
of Database (postgres or H2)