* refactor: Cache components' JS and CSS scripts at class creation time
* refactor: add test for no template_rendered signal for component with no template
* feat: add decorator for writing component tests
* refactor: udpate changelog + update deps pins
* refactor: fix deps
* refactor: make cached_ref into generic and fix linter errors
* refactor: fix coverage testing
* refactor: use global var instead of env var for is_testing state