fix waterfox support on macOS (#2080)

What it says on the tin. Very simple fix, just requires adding the app
bundle information to `firefox.py`. Also added an alternate
capitalization to the 'simple' app identifiers just in case.

If someone who daily drives Windows and Linux can double-check both of
those are working as well that'd be good; any fixes needed there could
be added to this as well (but I think the previous Waterfox pr should've
worked fine for both of those?).

Co-authored-by: Nicholas Riley <com-github@sabi.net>

Author: rinOfTheStars

apps/firefox/firefox.py

@@ -11,6 +11,7 @@
 apps.firefox = "app.name: firefox-esr"
 apps.firefox = "app.name: LibreWolf"
 apps.firefox = "app.name: waterfox"
+apps.firefox = "app.name: Waterfox"
 apps.firefox = r"""
 os: windows
 and app.name: Firefox
@@ -21,6 +22,11 @@
 os: mac
 and app.bundle: org.mozilla.firefox
 """
+apps.firefox = """
+os: mac
+and app.bundle: net.waterfox.waterfox
+"""
+
 
 # Make the context match more specifically than anything else. This is important, eg. to
 # override the browser.go_home() implementation in tags/browser/browser_mac.py.