jellyseerr already did this, but it's been standardised a little more.
Mediabrowser uses it's own genericErr function and error types due to
being a separate package, while jellyseerr and ombi now share errors
defined in common/.
log messages are very fragmented and are often repeated many times throughout the software with small differences.
Messages will be listed in logmessages/, which are simply strings with
formatting directives if necessary. So far, only main.go has been
completed.