Enable running subscription tests with oriole

Allow skipping transactions for ReorderBufferAbortOld()

Transactions need to be marked as RBTXN_DISTR_SKIP_CLEANUP to be skipped in
ReorderBufferAbortOld().

Add row_ref_equals hook for check_exclusion_or_unique_constraint to w…

…ork with rowid

Rework handling of running transactions by extensions.

 * RunningTransactionsExtension structure as a part of xl_running_xacts and
   RunningTransactionsData to be filled by extensions.
 * getRunningTransactionsExtension hook to fill RunningTransactionsExtension.
 * Add nextXid field to CSNSnapshotData.
 * SnapBuildGetCSNSnaphot() function to modify CSNSnapshotData in the
   SnapBuild.
 * waitSnapshotHook hook to wait for transactions inside the snapshot
   builder.

Rework handling of running transactions by extensions.

 * RunningTransactionsExtension structure as a part of xl_running_xacts and
   RunningTransactionsData to be filled by extensions.
 * getRunningTransactionsExtension hook to fill RunningTransactionsExtension.
 * Add nextXid field to CSNSnapshotData.
 * SnapBuildGetCSNSnaphot() function to modify CSNSnapshotData in the
   SnapBuild.
 * waitSnapshotHook hook to wait for transactions inside the snapshot
   builder.

Rework handling of running transactions by extensions.

 * RunningTransactionsExtension structure as a part of xl_running_xacts and
   RunningTransactionsData to be filled by extensions.
 * getRunningTransactionsExtension hook to fill RunningTransactionsExtension.
 * Add nextXid field to CSNSnapshotData.
 * SnapBuildGetCSNSnaphot() function to modify CSNSnapshotData in the
   SnapBuild.
 * waitSnapshotHook hook to wait for transactions inside the snapshot
   builder.

Rework handling of running transactions by extensions.

 * RunningTransactionsExtension structure as a part of xl_running_xacts and
   RunningTransactionsData to be filled by extensions.
 * getRunningTransactionsExtension hook to fill RunningTransactionsExtension.
 * Add nextXid field to CSNSnapshotData.
 * SnapBuildGetCSNSnaphot() function to modify CSNSnapshotData in the
   SnapBuild.
 * waitSnapshotHook hook to wait for transactions inside the snapshot
   builder.

Fix copying datum in ExecModifyTable()

Save the alignment.

Fix copying datum in ExecModifyTable()

Save the alignment.

fix pg_rewind docs