[Feature]: Unify Shell and Context

[MrPicklePinosaur]

What would you like to see added?

the Shell state variable holds non mutable global context whereas Context holds mutable global context. We can easily merge these two by putting the things that need to be mutated behind a RefCell, which some fields in Shell already are. This should reduce the amount of arguments we passing around and reduce noise in function signatures

[MrPicklePinosaur]

closing, refcell spam is not good idea