add id to menu in order to be used by cypress

rename cypress selector for login/logout

add cypress-io selectors

fix: 822 On production build, the override of endpoint url is not took into account on state relative to current page

- add option to allow demo mode (display theme selector)
- fix start:dlcmtest to use dlcmtest api and not just auth
- add option to force runtime setting override (usefull to test on dev env)