"tag" entity selector does not support colons

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Steps to Reproduce:
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Observed Results:
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Expected Results:
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Steps to Reproduce (1.21.1):
1. Drop a gunpowder item onto the ground.

2. A different bug related to copy/pasting the following command is interfering with with step. To simply resolve this issue, DO NOT copy/paste the following command and instead type it manually: "/data modify entity @n[type=item] Tags append from entity @n[type=item] Item.id". The server should return with the message "Modified entity data of Gunpowder".

3. While near the same item, run the command "/tag @n[type=item] list". The server should return with the message "The [X] entities have 1 total tags: minecraft:gunpowder"

4. Run the command "tag @e remove minecraft:gunpowder"

Observed Results:
Returned with error stating "Expected whitespace to end one argument, but found trailing data
... minecraft:totem_of_undying<–[HERE]"

Expected Results:
Returns with message saying "Removed tag 'minecraft:gunpwoder' from [X] entities"