Be able to edit mapping errors messages

[dsanti82]

Is your feature request related to a problem? Please describe.
Some of the Mapping Errors messages are clear and helpful, others are not.

Describe the solution you'd like
Either update the message to be more clear as to what the error is or add a hook that can be edited by custom code in theme.

Additional context

[jonathanstegall]

@dsanti82 currently no one is working on this plugin (I left MinnPost two years ago) but I still have access, and if you want to submit a pull request I can review and potentially merge it.