Consolidate Fluxon usage via CoreComponents

With the exclusion of 'button' which is already in use an may need a
refactor

lib/music_library_web/controllers/session_html/new.html.heex

@@ -9,7 +9,7 @@
       <div class="relative -space-y-px rounded-md shadow-xs">
         <div>
           <label for="password" class="sr-only">{gettext("Password")}</label>
-          <Fluxon.Components.Input.input
+          <.input
             id="password"
             name="password"
             type="password"