refactor: extend base settings add class to edit

src/app/components/settings-base-add-edit/settings-base-add-edit.ts

@@ -0,0 +1,13 @@
+import { FormGroup } from '@angular/forms';
+
+export abstract class SettingsBaseAddEdit {
+  abstract btnText: string;
+  abstract title: string;
+  abstract form: FormGroup;
+  
+  protected abstract submit(): Promise<void>
+
+  get disabled() {
+    return this.form.invalid || this.form.pristine;
+  }
+}