Implement ActivityInstance in FiberConfigDOM (#32842)

Stacked on #32851 and #32900.

This implements the equivalent Configs for ActivityInstance as we have
for SuspenseInstance. These can be implemented as comments but they
don't have to be and can be implemented differently in the renderer.

This seems like a lot duplication but it's actually ends mostly just
calling the same methods underneath and the wrappers compiles out.

This doesn't leave the Activity dehydrated yet. It just hydrates into it
immediately.

DiffTrain build for [17f88c8](17f88c8)

Author: sebmarkbage

compiled-rn/VERSION_NATIVE_FB

@@ -1 +1 @@
-19.2.0-native-fb-3fbd6b7b-20250422
+19.2.0-native-fb-17f88c80-20250422

compiled-rn/facebook-fbsource/xplat/js/RKJSModules/vendor/react/react-dom/cjs/ReactDOM-dev.js

@@ -7,7 +7,7 @@
  * @noflow
  * @nolint
  * @preventMunge
- * @generated SignedSource<<619fc57ea8661dca84d6a2d35efb44ac>>
+ * @generated SignedSource<<0b6590522eb4cf48244a47f0ae7bfc8f>>
  */
 
 "use strict";
@@ -404,5 +404,5 @@ __DEV__ &&
     exports.useFormStatus = function () {
       return resolveDispatcher().useHostTransitionStatus();
     };
-    exports.version = "19.2.0-native-fb-3fbd6b7b-20250422";
+    exports.version = "19.2.0-native-fb-17f88c80-20250422";
   })();

compiled-rn/facebook-fbsource/xplat/js/RKJSModules/vendor/react/react-dom/cjs/ReactDOM-prod.js

@@ -7,7 +7,7 @@
  * @noflow
  * @nolint
  * @preventMunge
- * @generated SignedSource<<a95808a94d4df1b94e07a099f06a7398>>
+ * @generated SignedSource<<2fafd8b44adafd221fec21bb898ac76c>>
  */
 
 "use strict";
@@ -203,4 +203,4 @@ exports.useFormState = function (action, initialState, permalink) {
 exports.useFormStatus = function () {
   return ReactSharedInternals.H.useHostTransitionStatus();
 };
-exports.version = "19.2.0-native-fb-3fbd6b7b-20250422";
+exports.version = "19.2.0-native-fb-17f88c80-20250422";

compiled-rn/facebook-fbsource/xplat/js/RKJSModules/vendor/react/react-dom/cjs/ReactDOM-profiling.js

@@ -7,7 +7,7 @@
  * @noflow
  * @nolint
  * @preventMunge
- * @generated SignedSource<<a95808a94d4df1b94e07a099f06a7398>>
+ * @generated SignedSource<<2fafd8b44adafd221fec21bb898ac76c>>
  */
 
 "use strict";
@@ -203,4 +203,4 @@ exports.useFormState = function (action, initialState, permalink) {
 exports.useFormStatus = function () {
   return ReactSharedInternals.H.useHostTransitionStatus();
 };
-exports.version = "19.2.0-native-fb-3fbd6b7b-20250422";
+exports.version = "19.2.0-native-fb-17f88c80-20250422";