Add pause function

[murapix]

Adding both a global pause function (thanks to pg132) and layer-specific pause functionality.

The intent of the pause functionality is to allow modders to stop spending processing time on hidden, unused, or completed layers, without impacting their functionality. If effective removal of a layer is desired, then pause() may be used in conjunction with deactived() to produce said effect.

While a layer is paused, all its various update loop functions will be skipped during the game tick, as well as any interactable components that may change its functionality will be uninteractable. Navigational components and toggle buttons, however, will remain usable. A specific call to each layer's pause functions exists outside the temp update loop in order to facilitate unpausing the layer, but is intentionally run after the update loop to allow for temp being filled out with initial values.