Rename operation to Sc_rollup_apply_outbox_effect (Follow-up from "Draft: SCORU: New manager operation for batched L2 to L1 messages")

The following discussion from !5379 (merged) should be addressed:

• @mbouaziz started a discussion: (+1 comment)

  @jobjo Indeed, we could think of a more generic name, for the operation and this field.

  Maybe something mentioning effect?

  (non-blocking)