Allow for Addons to export part of themselves to other addons

[zelcion]

Description

Some libraries are made to work together with other libraries, such as Express and Socket.io. Currently, MSYS has a completely isolated workspace for every added Addon, meaning no Addon can directly affect other Addons.

Solving Suggestion

We could create another Broker action that allows for Addons to export values, classes, and functions, and another action that enables their retrieval.