Beyond renaming it also adjusts whitespace and adds braces to conform to current doc/developer-notes.md.
TestEncrypt: Change iterator type to auto in ahead of vector -> span conversion.
Only touches functions that will be modified in next commit.
Move `SetKeyFromPassphrase` to out of LIMITED_WHILE,
remove `SetKey` calls since it is already called
internally by other functions and reduce the number
of iterations.
