Unifiy/consolidate error types in CHIP

[andy31415]

Problem

Chip generally has CHIP_ERROR used in most places, however we also have INET_ERROR and potentially others (posix calls will use errno, various libraries will have their own version)

Proposed Solution

Unify on one error type. Choices could be: conversion on CHIP_ERROR for all external purposes or have some compound error type (e.g. source and number to support saying <ERRNO, 2> or <CHIP, OUT_OF_MEMORY>).

[andy31415]

Same as #7688