Add sufficient typings to build main Firefox add-on code with --noImplicitAny
Add typings for 'sdk/self'
Fix autofill no longer working after activating link in tab

When navigating to a new page in a tab which has been autofilled,
the existing worker is detached and is no longer active.

Remove the worker from the tab ID => worker mapping in this
case so a new worker is set up when the user next activates
autofill in the tab.