Test PDF files should never be executable because we only read their
contents, so this commit makes sure that all test PDFs have the same
permissions, namely 0644 (read-only for all groups, and writable for the
owner), to limit their permissions for a least-privilege approach.
It's a follow-up of #14950: some format actions are ran when the document is open
but we must be sure we've everything ready for that, hence we have to run some
named actions before runnig the global format.
In playing with the form, I discovered that the blur event wasn't triggered when
JS called `setFocus` (because in such a case the mouse was never down). So I removed
the mouseState thing to just use the correct commitKey when blur is triggered by a
TAB key.
