feat: simplifies collapsible label API, adds e2e tests

src/fields/config/schema.ts

@@ -183,14 +183,13 @@ export const row = baseField.keys({
 });
 
 export const collapsible = baseField.keys({
-  label: joi.string().required(),
+  label: joi.alternatives().try(
+    joi.string(),
+    componentSchema,
+  ),
   type: joi.string().valid('collapsible').required(),
   fields: joi.array().items(joi.link('#field')),
-  admin: baseAdminFields.keys({
-    components: baseAdminComponentFields.keys({
-      CollapsibleLabel: componentSchema,
-    }).default({}),
-  }).default({}),
+  admin: baseAdminFields.default(),
 });
 
 const tab = baseField.keys({

src/fields/config/types.ts

@@ -186,15 +186,12 @@ export type RowField = Omit<FieldBase, 'admin' | 'name'> & {
   fields: Field[];
 }
 
-export type CollapsibleField = Omit<FieldBase, 'name'> & {
+export type CollapsibleField = Omit<FieldBase, 'name' | 'label'> & {
   type: 'collapsible';
-  label: string
+  label: RowLabel
   fields: Field[];
   admin?: Admin & {
     initCollapsed?: boolean | false;
-    components?: {
-      CollapsibleLabel?: RowLabel
-    } & Admin['components']
   }
 }