Refactor window state saving methods

[bsclifton]

For an example, see:
https://github.com/brave/browser-laptop/blob/master/js/components/main.js#L481

These events should be consolidated into one handler with a declarative event name, like onWindowParamsChanged which could then have optional arguments for:

• size
• position
• maximize / minimize
• focus

(and others as appropriate)