Move not UI-related torbutton.js code to XPCOM component/service

torbutton_init() is the entry point: we should start there, find out which code does not need to be loaded for every window and move it to a new or existing component.

Trac:
Parent Ticket: legacy/trac#28745 (moved)

added component::applications/tor browser in Legacy / Trac gitlab-tb-torbutton in Legacy / Trac owner::tbb-team in Legacy / Trac parent::28745 in Legacy / Trac priority::medium in Legacy / Trac severity::normal in Legacy / Trac status::new in Legacy / Trac tbb-torbutton in Legacy / Trac type::defect in Legacy / Trac labels

Add magic gitlab keyword.

Trac:
Keywords: N/A deleted, gitlab-tb-torbutton added

moved from legacy/trac#30850 (moved)

added Bug label and removed 1 deleted label

removed 1 deleted label

added Icebox label

closed

moved to tor-browser#40983 (closed)