Adds the ability to have per item transaction permissions

[NicholasJBond]

Resolves
#2212

Details
Adds the permissions essentials.item.<free|buy|sell>.<itemName>.

Players still need the permissions essentials.sell.<hand|inventory> and essentials.signs.<free|buy|sell>.use depending on which method they sell their items.

Example
A player needs essentials.item.sell.redstone in order to sell redstone(sign or command).

To keep existing behaviour
Set permission to essentials.item.<free|buy|sell>.* to allow all types or items to be sold.
Not sure if this should be added into the config file for example as: perItemTransactionPermissions: false or if server admins could add the above permission into their permission manager.

OS: Windows

Java version: 17.0.9

Minecraft 1.20.2

Paper Version used gradlew build :runServer

[imDaniX]

Not sure if this should be added into the config file for example as: perItemTransactionPermissions: false or if server admins could add the above permission into their permission manager.

I'd say this should, since this changes the current behavior.

[pop4959]

Similar comments as the other closed issue, appreciate this but needs to be more configurable, also have concerns around hard-coded messages, etc.