Revert _ random self/other naming str format hacks

This reverts commit 7e1a5b7cf7b4c4d3f868eba5dbea9e53a285e673
This reverts commit 6d3079c34f240b7a9b45158104b90c158ea0e439
This reverts commit c79af9a50109e1013329f3336f596486d84e14c4
underscore: SWP self, other in __r*__() fmaps

Breaks tests for repr/str equity
yet maintains equivalence when evaluating repr
Update rightside str conv tests: reverse order

The previous commit changed the representation of _
for rightside methods to a different yet equivalent