Fix tray icon handling on Windows (#2774)

[ElTh0r0]

Currently all tray icon options are ignored on Windows with #ifdefs, which is not needed from functional point of view. This patch removes these restrictions and user is able to decide if tray icon is wanted or not.

Only disadvantage: Since CLI parsing is currently disabled for Windows, users cannot reach the flameshot config GUI anymore after disabling the tray! So one has to edit the ini manually to restore the tray.

flameshot/src/main.cpp

Lines 149 to 153 in 57c8e8d

	#if !defined(Q_OS_WIN)
	/*--------------|
	* CLI parsing |
	* ------------*/
	new QCoreApplication(argc, argv);

Disabling the CLI for Windows might not be needed as well. If I find some time, I'll maybe have a look on this and test it (see #2118).

[borgmanJeremy]

The reason it is #ifdef'ed out is without the CLI parsing in place a user can be left with a half functional version of Flameshot.

Until CLI parsing is supported I do not want to allow windows users to disable the tray. I suspect this will lead to a deluge of bug reports.