jams-server: create the file handler api and edit form

jams-server/doc/index.html

jams-server/src/main/java/net/jami/jams/server/Server.java

...ms/server/servlets/api/admin/contacts/ContactServlet.java

...i/jams/server/servlets/api/admin/group/PolicyServlet.java

...ams/server/servlets/api/auth/contacts/ContactServlet.java

...mi/jams/server/servlets/api/image/FileHandlerServlet.java

...ava/net/jami/jams/server/servlets/filters/CorsFilter.java

...va/net/jami/jams/server/servlets/filters/FilterUtils.java