add get_level_name

[GammaGames]

Entity references look like this:

{
        [entityIid] = 8abfd930-3b70-11ee-84af-b5e40234e3c8,
        [layerIid] = a3b53eb0-3b70-11ee-973c-cfcdb685ef3c,
        [levelIid] = a3b4f090-3b70-11ee-973c-d982a01398d8,
        [worldIid] = e555a9c0-1460-11ee-8c5d-c3e63b15dcb2,
}

This adds a function to translate levelIid into the text name for load_level (I'm using to to connect doors between levels)