save the addon id earlier, after a successfull submission?

[eviljeff]

Right now the addon-id is saved in .web-extension.id after the xpi has been downloaded. If the approval check times out, or the user cancels the wait before the timeout, the addon-id isn't saved. If the user then decides to submit a new version they'll be creating a new add-on, possibly without realising(!)

This isn't an unlikely scenario - in the best case there are a few minutes of waiting after a successful submission, after it's been auto-signed by the cron job, and although the user may wait they may also conclude something is amiss before the approval is complete. But in many cases (i.e. the first listed version for an add-on) the signing is purposefully held back for up to 24 hours to allow it to be content reviewed; and in some cases the add-on will be chosen for manual review and signing could be delayed further depending on when it's submitted, review team capacity, etc.

With the submission api we know the addon-id immediately after a successfully request because it's returned in the response, so we could write the id immediately once we know an add-on will be created.