1680212 - Rename Watcher classes's watch method to initialize

Status: NEW

(DevTools :: Framework, enhancement)

Description

[Alexandre Poirot [:ochameau]]

See this review comment for more context:
https://phabricator.services.mozilla.com/D87504?id=372538#inline-554598

Today, Watcher classes have to implement two methods: watch and destroy.
watch could, in theory be merged into the constructor, it originaly was.
But because this is async we introduced an async method.
Given that this is still an initialization method that is meant to be called only once, this would probably be better named initialize.