notifications (and windows msi installer)

[casperstorm]

This PR adds notification support, along a few events: Connected, Reconnected and Disconnected.
We should add more, but for now the base should be ready.

Reason this PR also includes a new installer for Windows is that in order to get a icon on the notification on Windows we need a app_id, and the easiest way (that i know of) is to do it through a .wxs file. For that reason we might as well produce a .msi installer as our "primary" windows installation. Going forward we could then use a default .exe asset for our "portable" installer (#141) - this would then be similar to how Alacritty does releases and assets.

In any case, with the app installed through the .msi installer notifications has a small icon which looks great.

Sounds

The configuration can take a string to a sound. Each OS has a different set of default sounds, depending on OS version as well. However in order for the user to know what to pick, we need to make a entry to our wiki with the different defaults and how to find them (see below).

This entire branch is currently untested on Linux - @tarkah could you test this?

macOS (/System/Library/Sounds/)

Basso
Blow
Bottle
Frog
Funk
Glass
Hero
Morse
Ping
Pop
Purr
Sosumi
Submarine
Tink

Windows (https://github.com/allenbenz/winrt-notification/blob/main/src/lib.rs#L70-L75)

Default
IM
Mail
Reminder
SMS

Unix (https://github.com/hoodie/notify-rust/blob/main/src/hints.rs#L68)

message-new-instant
[...]

Fixes #203

[casperstorm]

@tarkah what do you think we should add before merge?

• DM notification?
• Highlight notification?