Remove rebar3_hex_utils and reorganize per removal

[starbelly]

This PR is part of an "epic" to reorganize, cleanup, improve tests, add docs and support organization transfers. There are at least 4 PRs to follow. As such, a release should not be made until the "epic" is complete.

This PR :

• Removes rebar3_hex_utils and re-organizes the functions that lived in that module.
• Provides a few minor fixups and/or enhancements, namely in the form of rebar3_hex_errors as a "catch all" that command modules can call out to in the case of an error that is unknown.
• Removes erlware_commons dependency by introducing rebar3_hex_io module

[starbelly]

Closing to combine this with #134