NBT suggesting (the curly brackets) is not present in the /clear command when using an item tag.

Expected behavior:
The NBT argument suggests opening and closing brackets.

Observed behavior:
Nothing is suggested further, and the next possible argument (<maxCount>) is shown instead.

Steps to reproduce:

1. Type /clear @s minecraft:anvil
2. Observe how { is suggested.
3. Clear chat
4. Type /clear @s #minecraft:anvil
5. Observe how NO { is suggested.