Closes https://gitea.subcultureofone.org/greg/tkr/issues/43 Use a global $app dictionary to manage global state rather than having complex class constructors that expect three input arguments. Update and fix tests. Add tests for Util class functions that broke in the refactor. Reviewed-on: https://gitea.subcultureofone.org/greg/tkr/pulls/44 Co-authored-by: Greg Sarjeant <greg@subcultureofone.org> Co-committed-by: Greg Sarjeant <greg@subcultureofone.org>