Fix hexadecimal numeric rendering in unit tests

[kammce]

Many of the ostream overloads change the base to hex. This needs to be reverted after each usage using std::cout.copyfmt(std::ios(NULL));.

https://stackoverflow.com/questions/4217704/roll-back-or-undo-any-manipulators-applied-to-a-stream-without-knowing-what-th

[MaliaLabor]

.take