Argument parsing rework (#1940)

* Experimental argument handling

* Restored browser extension launch functionality

Also moved check from BrowerExtension.cpp to Args.cpp as it is more relevant there and doesn't require passing arguments to a function in another file

* Fixed formatting

* Simplified Args.cpp code, added changelog entry

* Hid crash-recovery from help

* Dont save settings if launched with --channels

* Changed parsing method to t:channel

* Code cleanup

* Changed plaform delimeter to :, platform defaults to Twitch

Co-authored-by: fourtf <tf.four@gmail.com>

src/BrowserExtension.hpp

@@ -1,10 +1,7 @@
 #pragma once
 
-class QStringList;
-
 namespace chatterino {
 
-bool shouldRunBrowserExtensionHost(const QStringList &args);
 void runBrowserExtensionHost();
 
 }  // namespace chatterino