Add __tostring() metamethods (with useful formatting and colorization) for all "class"-style modules

[Duckwhale]

Goal: If someone prints one of those objects, the output should be something more useful than table: 0xdeadbeef.

Should be somewhat consistent with the JS developer tools (can change the colors later, if need be).

• All "class"-style modules should support have a __tostring metamethod that prints a useful representation of properties
• This output should be colorized in a standardized fashion, using fixed colors for class name, property name, values
• To make this simpler, can add something like COLORIZE_CLASS_NAME or COLORIZE_BOOL_PROPERTY
• Either put this into the transform library, or possibly oop if it has been implemented by then (?)

In this context, "class-style modules" means anything with a Construct function (and according __call metamethod).

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Probably requires #387? Later, can extend this to colorized dump output maybe? (separate issue)