Change item id offsets to protect basegame ones

[EvelynTSMG]

Maintenance

Some item id prefixes are already used by the game (0x3000 applies to all commands, not just overdrives, etc.)
To better separate these from the game's, it would be good to make sure Archipelago-exclusive offsets have a unique prefix. This is most easily done by adding 1 at the start: the prefix for overdrives would become 0x13000.

[Rurusachi]

Archipelago items intentionally use the same id as the game item they represent when possible. The Overdrive offset could be renamed Command instead.
Additionally the third byte is currently used to indicate quantity for normal items (and possibly other items in the future) so if we need more item categories we should move quantity to the fourth byte

[EvelynTSMG]

I agree with renaming Overdrive to Command, which would also someday be used by the Sphere Grid rando presumably
I agree with Archipelago items using basegame prefixes when the category matches, however some of the categories (otherItemOffset being 0xC000) is unideal, since someone might confuse it for a basegame prefix (even if 0xC000 is never discovered as a prefix used in basegame code).
Instead of using the third byte, this change could use the fourth byte by making the numbers negative when unique: such that otherItemOffset would be -0xC000 i.e. 0x8000C000

[Rurusachi]

According to the Archipelago docs item (and location) ids are supported in the range [-2^53 + 1, 2^53 - 1] but 0 and lower are reserved. So while we can do 0x8000C000 I think it would make more sense to just move quantity to the fourth byte and use the third byte for other information to keep category-related information together