[Task]: Button to remove uploaded file if the review message was not sent

[ialecse]

Description

As a reviewer I might want to remove the file I selected to be attached to the review message, if I didn't already sent the message to developer. Right now the only way to remove a selected file is to close the review page and open it again. There should be an action button to allow removing the uploaded file.

Acceptance Criteria

  ### Milestones/checkpoints
  - [ ] Remove uploaded file feature

Checks

• [X] If I have identified that the work is specific to a repository, I have removed "repository:addons-server" or "repository:addons-frontend"

┆Issue is synchronized with this Jira Task

[diox]

Yeah we should add a clear button or something to that form.

[ioanarusiczki]

Fixed on dev