Move all notifications into renderer process from main process

[cassidoo]

Right now notifications are spread between the main and renderer processes.

They should all be moved to the renderer process, so we can add custom sounds for them, and control messages from the main process better.

[ApurvaBasule]

@cassidoo can i work on this issue?

[cassidoo]

@ApurvaBasule sure thing, go for it!
I admit I started it and didn't get far because of some other responsibilities coming up, so I'd love to see your approach and maybe some of my code can be merged with yours, hahaha.

[cassidoo]

@ApurvaBasule any progress?