Start the backtrace generator as soon as the dialog opens
Starts implementing part of BUG: 383923.
Here's a rundown of the changes:
- Start loading the backtrace information immediately, from what I can see there's no blocking on the UI so this is relatively harmless.
- Disable the "Developer Information" (backtrace) action until the backtrace has loaded, there's no point in going in there anyway before it loads (and I want to attempt to reduce the amount of states that page will handle in the future).
- Show a progress bar when loading and change the status text to make it obvious that the user should wait a minute or two.
You might notice while testing that the cursor changes to a busy cursor even though we have a progress bar, unfortunately changing this will be a little bit more involved - it seems that the Widgets version is loaded in the background and that's controlling the cursor.