Add config option to remember last active inventory-setup,

[1Defence]

Loads on plugin/client startup, the config value is cleared if you close a setups view, prior to closing the client to prevent weird cases of a user getting thrown back into a setup when they didn't want it.

https://github.com/dillydill123/inventory-setups/assets/63735241/fde5640a-5331-449b-9b28-23bc354cfa7a