2.15.1 - Ensure error messages thrown by data decoding provide useful information

What's Changed

Ensure error messages thrown by data decoding provide useful information by @gwynne in #277

Under some conditions, a failed attempt to decode data from an SQLRow (whether via SQLKit or through Fluent) would throw errors whose descriptions were missing information critical to understanding the problem. This fixes that.

Also adds some useful notes about using PostgresKit with PostgresClient to the README.

Reviewers

Thanks to the reviewers for their help:

• @MahdiBM

This patch was released by @gwynne

Full Changelog: 2.15.0...2.15.1