move getMessage to meta_data?

[andre-merzky]

Is your request related to a problem? Please describe.
I am find the usage of the status message attribute unclear / unclean. (a) according to @hategan, it is supposed to convey error messages on FAILED states - but that means that the field is only usable in that state. But also, (b), I consider the meta_data dict to be the catch-all for any non-standardized, backend specific information, and an error message would fit that bill.

Describe the solution you'd like
A clear and concise description of what you want to happen.

Describe alternatives you've considered
remove Status.getMessage.

Additional context
I am uncertain about this - this may be more a request for clarification / discussion than for immediate change. Maybe making the name clearer (getMessage -> getError) would also work, to make the intent and scope clear.

[hategan]

Would renaming it to getErrorMessage make more sense?