feat(directory): Add oracle for event testing (#25477)

This change introduces a new oracle SharedDirectoryOracle for validating
ISharedDirectory
event correctness and API contracts. The oracle maintains two separate
models tracking
directory state through different event streams to ensure both event
types report changes
consistently.

Key features:

- Maintains two nested tree models: one tracking valueChanged events
(global), one tracking
  containedValueChanged events (per-directory)
- Validates previousValue correctness in events, accounting for
optimistic operations and
  post-clear events
- Post-clear events: previousValue has pre-clear value, oracle already
cleared → expected mismatch
- Remote ops with pending local ops: previousValue is sequenced, oracle
is optimistic → expected mismatch
- Validates actual directory state matches oracle models using
validate() method
-  Subscribed events:
   - valueChanged, containedValueChanged: Track key changes
   - clearInternal: Track directory clears
- subDirectoryCreated, subDirectoryDeleted: Track subdirectory lifecycle
   - disposed, undisposed: Handle rollback scenarios
 
Bugs:

[ADO#54515](https://dev.azure.com/fluidframework/internal/_workitems/edit/54515)

Author: sonalideshpandemsft

packages/dds/map/src/directory.ts

@@ -1913,11 +1913,13 @@ class SubDirectory extends TypedEventEmitter<IDirectoryEvents> implements IDirec
 			}
 
 			// For pending set operations, emit valueChanged events
+			// Include 'path' so listeners can identify which subdirectory the change occurred in
 			for (const { key, previousValue } of pendingSets) {
 				this.directory.emit(
 					"valueChanged",
 					{
 						key,
+						path: this.absolutePath,
 						previousValue,
 					},
 					local,