Glowing does not work on text displays

Closely relates to MC-307625, MC-308920 and MC-308921.

For some reason, unlike basically every other entity that exists in the game, text displays look no different from normal if the glowing property is set to true. This is inconsistent.

To reproduce: /summon text_display ~ ~2 ~ {text:'HERE\'S SOME TEXT',Glowing:1b}

Expected result: this text display would have a glowing outline like other entities.

Actual result: a rather typical looking text display.