Rename several interfaces that were in the style IWhatever, which Java
doesn't use

This fixes two failing tests
* One was that when refactoring AestheticDirective, I accidentally
  broke doing padding before the value.
* The other was that when allowing for using multiple ` on a directive,
  I accidentally broke parsing for ` directives

This implements a general directive for float printing (~`D). In the
long term, instead of this directive, a more specific one (probably
implemented by a macro or something) should be used

Part II of the cleanup pass

utils.esodata now also lives in the esodata project; not here