Replace a couple useless string evals with their equivalent

Dliberately *not* using Module::Runtime, future improvements will
replace ->ensure_class_loaded with something less volatile
HRI is part of a pretty hot codepath, just load it all the time
These loads are no longer necessary after d7d45bdc65
These are already pre-required by the OptDeps check
Fix incorrect collapser source being generated due to unicode collapse points

I am not sure how nobody but abraxxa ran into this - the missing escapes have
been used by a ton of people for over a year. In any case the issue is real,
and fixed by trivial {}-escaping.

Add an extra stresstest envvar to make sure this does not regress in the
future (the envvar will be picked up and set by POISON_ENV on travis)
Fix idiocy that snuck in bdbd2ae8a - I only want fatal undefs

Not sure what I was thinking. In either case - remove the unsafe code, and
annotate the remaining uses of FATAL => 'all'
Bump Moo dependency
Minor cleanup
Fix endless loop on BareSourcelessResultClass->throw_exception(...)

There is a better fix for this in the pipes, but this will do for now