Simplify task creation for reviewers

As a PR creator, the main reason I visit Bitbucket is to see what changes I need to make to my PR. I think tasks are a great way to achieve that but there are a number of problems which make tasks difficult to use.

It's frustrating for the PR creator to have to create tasks themselves based on comments on a PR. Even though it's relatively simple and the comment context is preserved, it's a strange back-and-forth between commenter and PR creator – I feel like it would make more sense for the commenter to create tasks and the PR creator consume them. However, after many PRs, I've never seen a commenter create a task. Ideally, task creation would be somewhat automated and seamless, much like mail clients suggest creating calendar events.