Fix gap in micro menu in Classic Era

[ehedbor]

Issue

In WoW Classic Era, the micro menu had a gap between the world map and main menu icons. This was caused by the presence of the LFG micro button in the global variable MICRO_BUTTONS. As Classic Era does not have a dungeon finder, this button does not exist in era.

Solution

This merge request manually defines the necessary buttons for Classic Era.

[Nevcairiel]

I simplified the entire thing in b3cbd2a