Audit error reporting in states, fix traceback

This commit audits error reporting, normalizing some of the terminology.
In addition, it fixes a traceback when state.template is called and
there is an empty short-dec with a trailing colon.

It also gives a more meaningful error message when the same thing is
done and state.sls/state.highstate is run.
Change default outputter for state.template/template_str
Fix tests to match new error messages
Fix misspelling
More test fixes
Merge pull request #12176 from terminalmage/issue11359

Audit error reporting in states, fix traceback in state.template