Removes old state load/save from each project file type, and the
unused WarnAsError property, in preparation for xmlLdmlProjectFile.

…jects

Adds XmlLdml keyboard editor form based on the plain text Editor for
now.

ActiveEditor is a name used for multiple purposes. Rename to
ActiveKmnKeyboardEditor and introduce ActiveLdmlKeyboardEditor
alongside.

Because the debugger actions are used only with the kmn keyboard editor,
it makes sense to keep them as a separate module, in preparation for
supporting XmlLdmlKeyboards.

Adds actions to support LdmlKeyboardEditor, and refactors and
reorganizes the existing actions along the way to make them clearer.

Compile, Install, and Uninstall supported at this time