feat: only pick up items if they are from the same build mode

[sekwah41]

This should fix #7 as well as avoid having items not from the build mode menu being able to get into there. Hoever if we dont have the block drops off the blocks dropped would still spawn without the tag so not sure if this 100% fixes the issue.

[sekwah41]

Just let me know if there is anything else needed to help close the issue.

[Gegy]

Nice! This works great for having tile drops off.
In general, I think we should mark any blocks dropped from a build mode player mining a block (or, more generally any loot table evaluating due to that player).

[sekwah41]

I held off on the block drops from build mode entirely being set just in case there were edge cases I wasn't thinking of, that plus no tile drops would mean its not an issue for now at least. We can take a look at altering that logic in another pr though ^.^ Im going to merge this for now as its a useful upgrade in its current state.