Some items, like 'Nether Sprouts', 'Spore Blossom', 'Small / Medium / Large Amethyst Bud' are offset or not centered on the creative menu. (That includes Search Tab and Categories)

Steps to reproduce: 

1. Open / create a world with creative mode enabled.
2. Open the creative menu and find / search for any of the above mentioned items.

Observed Behavior (Observed-1.png):

•   Spore Blossom is not centered and offset to the top.
•   Small / Medium / Large Amethyst Bud are not centered and offset to the bottom.
•   Nether Sprouts are centered, although other similar items (Warped / Hanging Roots, Crimson / Warped Fungus are not.)

Expected Behavior (Expected-2.png):

•  Spore Blossom is centered.
•  Small / Medium / Large Amethyst Bud are centered.
•  Nether Sprouts are offset to the bottom as other similar items.

Edit: This seems to be caused by the inconsistency of the texture placements on the Creative Menu. Some are offset based of their possible placement in the world (Like all the pressure plates), but some are just centered (Like the Lightning rod and the Big / Small Dreapleaf).

This is a trivial issue, but I think it should be mentioned.