refactor: address loading review findings (#18)

frontend/src/app/components/apartment-form/apartment-form.css

@@ -27,17 +27,6 @@
   background: var(--surface);
   box-shadow: 0 1px 0 rgba(255, 255, 255, 0.04);
 }
-fieldset {
-  min-width: 0;
-  margin: 0;
-  padding: 0;
-  border: 0;
-}
-.primary-action mat-spinner {
-  display: inline-block;
-  margin-right: 8px;
-  vertical-align: middle;
-}
 .form-grid {
   display: grid;
   grid-template-columns: minmax(0, 1fr);