Some Error Codes Collide

[Mythra]

While looking into parsing errors inside of my crate to show slightly nicer error messages for my application specifically I've noticed that there seem to be several error codes that collide. Specifically the module error codes export CE02, and CE03 for the cause: CANNOT_IMPORT_ERROR_CODE, and BORROW_ERROR_CODE:

starlark-rust/starlark/src/environment/mod.rs

Lines 34 to 35 in 2002bb1

	const CANNOT_IMPORT_ERROR_CODE: &str = "CE02";
	const BORROW_ERROR_CODE: &str = "CE03";

However, these are also exported by the common evaluation error codes:

starlark-rust/starlark/src/eval/mod.rs

Lines 82 to 84 in 0942470

	pub const RETURN_ERROR_CODE: &str = "CE02";
	#[doc(hidden)]
	pub const INCORRECT_LEFT_VALUE_ERROR_CODE: &str = "CE03";

These error codes don't seem to line up either RETURN_ERROR_CODE != CANNOT_IMPORT_ERROR_CODE in my mind. Are these simple typo's or do they represent the exact same error case?

[damienmg]

Those are definitely error code clashes, that's why there is a TODO somewhere to have all error code in one place :)