removed obsolete GameManager (unused code)

[fmuecke]

GameManager is a relict from Awtrix2 and no longer used in Awtrix3. Thus it can be removed.

[Blueforcer]

It can't be a relict, because the code has nothing to do with awtrix 2. different language, different code.
It's just not finished yet..

[fmuecke]

But still, does not seem to be of any use atm. "Ist das Kunst, oder kann das weg?"

[Blueforcer]

Nur weil's nicht fertig ist, bedeutend es nicht das es weg kann😅 Stört ja niemanden bis dato