[BUG FIXES]
- exceptions should not throw other exceptions; fixes cases where exceptions
were reporting the wrong error (Upasana, RT#92818 and RT#94795)
[OTHER]
- prereqs needed strictly for building with Dist::Zilla have been moved from
develop requires to develop recommends, to simplify automated testing on
older perls that cannot install all Dist::Zilla components
- removed instances of metaobjects in exception classes where they're not
really required