Unify error codes / messages

[TristonianJones]

Issue Filing Checklist

• There are no issues that match the desired change
• The change is large enough it can't be addressed with a simple Pull Request

Change

Error messages are formatted strings which are not uniform. While this was
okay for development, the errors should be consolidated into error codes
with a set of associated details. Further, when multiple errors are encountered
they should be aggregated together rather than simply picking the first one.

Proposed error codes:

Code	Details	Description
ATTRIBUTE_NOT_FOUND	type, attribute	Map or object access using an unknown attribute.
DIVIDE_BY_ZERO	n/a	Division by zero, also reported for modulus operations.
DUPLICATE_ATTRIBUTE	attribute name	Map or object construction supplies same key value more than once.
IDENTIFIER_NOT_FOUND	identifier name	Variable or function name could not be found.
INVALID_ARGUMENT	argument value	Invalid argument supplied to a function.
OVERLOAD_NOT_FOUND	function signature	Function defined, but no matching overload found.
TYPE_NOT_FOUND	type name	Type definition could not be found.

Example

return types.NewError(errors.ATTRIBUTE_NOT_FOUND, value.Type(), field)

[josephschorr]

Hi @TristonianJones, any updates on this? We would find it incredibly useful to be able to provide better errors messages when CEL evaluation fails.

Happy to help if need be.