Vanilla Commands should be namespaced

Currently, vanilla minecraft commands are not namespaced.

In the Minecraft Bedrock Script API, Minecraft will automatically register a version of the custom command without the provided namespace (e.g. /placeblock as well as /example:placeblock).

If a custom command like /example:say was added via the Minecraft Bedrock script with different functionality (like message numeric ids built into the script instead of plain text strings), then Minecraft's vanilla /say command might stop working or not work properly as a result.

To fix this, all of Minecraft's built-in commands should have a namespaced version such as for example:

• /minecraft:say
• /minecraft:teleport

This makes things easier for add for Minecraft Bedrock add-on developers.