Statement replicas do not trigger onStatementAdded()

Discovered during YANGTOOLS-1385 development, issuing a StmtContext.replicaAsChildOf() does not trigger StatementSupport.onStatementAdded().
This method was introduced in YANGTOOLS-1184 and related effort, but the behaviour has always been that the statements introduced in places which use replicaAsChildOf() did not trigger the codepath.

This is problematic, as statements introduced though this mechanism do not see the statement being instantiated in target context, and hence cannot perform statement-specific inference-based validation – like attempted in YANGTOOLS-1385, where an 'unique' statement can be introduced via 'deviate add' – and it should run validation in the target list context, not in its original declaration site.