#24 Clean up translation

Translations were added and removed as development went on. Some translations are never used and there is no standard for how translation keys are named or grouped.

Some things to take note of are common elements like pane headers and appending or prepending the control type to the key like "copyPoseButton" or "ikToggle."

Something else to consider is that there are a handful of duplicate translations. Could just leave it alone and give the user more flexibility in translating.

Another area to look at are the translation files. Right now they're broken down into "bg," "face," "props," and "ui." Another file could be added that houses longer translation strings like confirmation messages or hotkey descriptions.

The UI is also optimized for the English translation strings I provide so that needs to be looked at as well.

Reopening because I referenced the wrong issue..