Inventory Manager refactoring and new features

[SirEndii]

The inventory manager was an early feature and didn't really follow any rules
After some time, I changed the syntax of the functions so they use our new ItemFilter
What I want to check/refactor:

• Slot numbers - Do they make sense how we access the armor and offhand slot, do we want to follow another/more popular standard there
• Function names - Some of the functions could need some better names
• Something else? - Just testing the inv manager before I mark this issue as done

One feature which I saw was requested often is, that the inventory manager should be able to provide a CC Generic inventory object so it can just be used as any cc inventory like a chest

Features I want to add:

• CC Inventory Object - Add a function to return a CC Generic Inventory Object
• Add items with capabilities - When for example a hopper tries to push items into the inventory manager, directly add the item to the user
• Permissions and Multiple Cards - This is optional and could maybe be too much work for now - So support that multiple players could be added to one inventory manager. But this would need an even more refactoring for something that is maybe not really used that much

[zyxkad]

I honestly don't think bind multiple player into one inventory manager is a good idea. This needs much more complex APIs.

[SirEndii]

Yeah I need to agree

[zyxkad]

• Slot numbers - Do they make sense how we access the armor and offhand slot, do we want to follow another/more popular standard there

Maybe we can provide dynamic slot offsets, which will return in getArmorSlotOffset(), getOffhandSlotOffset(), getCuriosSlotOffset() and such.
And if the slots do not exist, we can return -1