Improve Dogtail's performance
Currently we run each command in its own script, importing all modules
and initiating Dogtail each time, and many commands depend on re-compute
previous results. Our
.children() method is particularly bad in this
We should instead run all Dogtail commands in a persistent Python session so results can be stored between Dogtail commands.
Feature Branch: test/12059-dogtail-optimizations
Blocked by #11887 (closed)