Note: Broadcast operations in BATCH mode don't yet work with this
change. This needs follow-up changes from later commits. We just lay the
groundwork here and keep the same functionality.

Before, we were creating operators in BroadcastConnectedStreams eagerly.
Now, the transformation holds the user function and we add a Translator
that creates the "physical" operators when translating the graph of
Transformations.

We do this so that we can translate differently based on whether we're
in BATCH or STREAMING mode.

Because that's what it does.

[FLINK-20766][table-planner-blink] Introduce BatchPhysicalSortLimit, and make BatchExecSortLimit only extended from ExecNode

This closes #14502

[FLINK-20766][table-planner-blink] Introduce BatchPhysicalSort, and make BatchExeSort only extended from ExecNode

This closes #14502

[FLINK-20766][table-planner-blink] Introduce StreamPhysicalTemporalSort, and make StreamExecTemporalSort only extended from ExecNode.

This closes #14502

[FLINK-20766][table-planner-blink] Introduce StreamPhysicalSortLimit, and make StreamExecSortLimit only extends from ExecNode.

This closes #14502

[FLINK-20766][table-planner-blink] Introduce StreamPhysicalSort, and make StreamExecSort only extended from ExecNode

This closes #14502

[FLINK-20782][table-planner-blink] Introduce BatchPhysicalRank, and make BatchExecRank only extended from ExecNode

This closes #14506

In particularly, if task is idling forever, as there are no new records incomming
previous version would report idleTime as 0% and busyTime as 100% which is incorrect.

In this version, idleTime metric is aware that idling period has started and can take
that into account when updating it's value.

It's defined as inverted value of idleTimeMsPerSecond

This closes #14467

This closes #14563

[FLINK-20737][table-planner-blink] Introduce StreamPhysicalPythonGroupTableAggregate, and make StreamExecPythonGroupTableAggregate only extended from ExecNode

This closes #14478

[FLINK-20737][table-planner-blink] Introduce StreamPhysicalGroupTableAggregate, and make StreamExecGroupTableAggregate only extended from ExecNode

This closes #14478

[FLINK-20737][table-planner-blink] Introduce StreamPhysicalIncrementalGroupAggregate, and make StreamExecIncrementalGroupAggregate only extended from ExecNode

This closes #14478

[FLINK-20737][table-planner-blink] Introduce StreamPhysicalGlobalGroupAggregate, and make StreamExecGlobalGroupAggregate only extended from ExecNode

This closes #14478

[FLINK-20737][table-planner-blink] Introduce StreamPhysicalLocalGroupAggregate, and make StreamExecLocalGroupAggregate only extended from ExecNode

This closes #14478

[FLINK-20737][table-planner-blink] Introduce StreamPhysicalPythonGroupAggregate, and make StreamExecPythonGroupAggregate only extended from ExecNode

This closes #14478

[FLINK-20737][table-planner-blink] Introduce StreamPhysicalGroupAggregate, and make StreamExecGroupAggregate only extended from ExecNode

This closes #14478

This closes #14478

Removing the ProgrammedSlotProvider since it is no longer used.

Moved the factories of the CompletedCheckpointStore and the CheckpointIDCounter to
SchedulerUtils in order to make them reusable.

By moving the shut down of checkpoint services out of the CheckpointCoordinator,
it is now possible to reuse these services across different CheckpointCoordinators.

This closes #14553.

[hotfix][tests] Replace explicit ExecutionGraphBuilder.buildGraph calls with TestingExecutionGraphBuilder

[FLINK-20846] Factor out CompletedCheckpointStore and CheckpointIDCounter creation in ExecutionGraphBuilder.buildGraph

Apply spotless formatting

This closes #14425.