Draft: Apply prefilter when an operation is injected locally

Context

Since !3345 (merged), an operation is prefiltered after a flush. This means that when an operation is injected locally, the only time it is not prefiltered is the very first time it is applied by the mempool. This situation is actually awkward in terms of semantics and we solve that here.

We also comment the implementation of this function for later modifications.

Fixes #2077