Some methods in TenantOplogApplier are very long and difficult to navigate such as writeNoop. We need to keep TenantOplogApplier for Shard Merge so we should improve this method to split it into understandable methods.

In this ticket we aim to improve readability by breaking up these large methods into smaller ones. We should also take note of other possible improvements in tenant oplog applier and raise tickets for them (unless these improvements are trivial and can be done in the same PR with negligible impact).