"Resume editing" would do nothing when going through the `/new-message` flow.
This seems to be broken since [this commit](b0f6d074be). which moved `this._setModel` calls around – the same we're doing now, but to different places: the first one needs to happen after the `draft.data` has been set , while the second needs to happen before the `this.open` call.
This commit will now change two behaviors:
- If composer is already opened on a specific post and we click on edit again for the same post, we will do nothing and not show the discard draft modal
- if composer is shrinked and we click on edit for the same currently edited post, we will just open the composer and not show the discard draft modal
