### What changes were proposed in this pull request?
Observable metrics are named arbitrary aggregate functions that can be defined on a query (Dataframe). As soon as the execution of a Dataframe reaches a completion point (e.g. finishes batch query or reaches streaming epoch) a named event is emitted that contains the metrics for the data processed since the last completion point.

A user can observe these metrics by attaching a listener to spark session, it depends on the execution mode which listener to attach:
- Batch: `QueryExecutionListener`. This will be called when the query completes. A user can access the metrics by using the `QueryExecution.observedMetrics` map.
- (Micro-batch) Streaming: `StreamingQueryListener`. This will be called when the streaming query completes an epoch. A user can access the metrics by using the `StreamingQueryProgress.observedMetrics` map. Please note that we currently do not support continuous execution streaming.

### Why are the changes needed?
This enabled observable metrics.

### Does this PR introduce any user-facing change?
Yes. It adds the `observe` method to `Dataset`.

### How was this patch tested?
- Added unit tests for the `CollectMetrics` logical node to the `AnalysisSuite`.
- Added unit tests for `StreamingProgress` JSON serialization to the `StreamingQueryStatusAndProgressSuite`.
- Added integration tests for streaming to the `StreamingQueryListenerSuite`.
- Added integration tests for batch to the `DataFrameCallbackSuite`.

Closes #26127 from hvanhovell/SPARK-29348.

Authored-by: herman <herman@databricks.com>
Signed-off-by: herman <herman@databricks.com>