Add the web-based launcher to the HTML5 demo dropping original
launcher. It includes changes to the launcher to match the new
navigator.appservice API and JS injection and drops agl-js-api.
Bug-AGL: SPEC-4249
Change-Id: I02a68fc81693a56aa19e213e8ee200c0ec4e3f42 Signed-off-by: Jose Dapena Paz <jdapena@igalia.com>