Adds item level overlay text to items in AdiBags.
When the player is level 0-59:
If the item has a required item level, display that level and color:
If the required level is higher than player level, red
If the required level is 8 or more levels below player level, gray
Otherwise, color is the item rarity color
If the item doesn't have a required item level, the item level is displayed and the color is the item rarity color
When the player is at level 60, the item level is displayed and the color is a gradient from ilvl 58 to 90. Items with an ilvl below 58 are colored gray.