Improve error messages

[CapsAdmin]

At the moment error messages are a bit all over the place. In some cases the token nodes that the error points to is also not always correct.

I've thought about representing errors with a "because chain", not sure if this is practically useful or if it's just a neat idea. Something like this:

local A = {
    foo = true,
    bar = false,
    faz = {
        one = 1,
        two = 2,
    }
}

local B = {
    foo = true,
    bar = false,
    faz = {
        one = 1,
        two = 3,
    }
}

A is not a subset of B because
A.faz is not a subset of B.faz because
A.faz.two is not a subset of B.faz.two because
2 is not the same literal as 3

It's a bit similar to a stack trace. The problem I have with stack traces is that it's not always useful to see all of the stack, but figuring out which level to cut out is not easily solvable.

[CapsAdmin]

I started doing this and it feels easier to me to read than i was expecting. Especially when it's split in newlines.

At the moment, this case is obviously too verbose

_G does not contain "Token" 
because "Token" is not the same value as "__name"
"Token" is not the same value as "return_type"
"Token" is not the same value as "argument_type"
"Token" is not the same value as "exclude"
"Token" is not the same value as "Tuple"
"Token" is not the same value as "enum"
"Token" is not the same value as "error_inside_base_environment"
"Token" is not the same value as "keysof"
"Token" is not the same value as "type_assert"
"Token" is not the same value as "subset_of"
-- ETC

I'm thinking I should embrace verbosity and then simplify the message when displaying the error.

Random quick thought, maybe even use a "language" that is easily parsable that then generates the proper error in English.

"Token" not in _G:
_G["Token"] != "__name",
_G["Token"] != "__name",
_G["Token"] != "__name",
-- ETC