feat(endpoints): add the ability to browse offline endpoints (#2253)

* feat(back): saved data in snapshot

* feat(endpoints): adding interceptors to retrieve saved data on offline endpoints

* feat(endpoints): offline dashboard working - need tests on offline views

* refactor(endpoints): interceptors cleaning and saving/loading offline endpoints data in/from localstorage

* feat(endpoints): browsing offline endpoints

* feat(endpoints): removing all the link in offline mode - sidebar not working when switching between off and on modes w/ stateManager logic

* feat(endpoints): endpoint status detection in real time

* fix(endpoints): offline swarm endpoint are not accessible anymore

* fix(endpoints): refactor message + disable offline browsing for an endpoint when no snapshot is available for it

* fix(endpoints): adding timeout and enabling loading bar for offline requests

* fix(endpoints): trying to access a down endpoint wont remove sidebar items if it fails

* feat(endpoints): disable checkboxes on offline views for offline mode

* feat(endpoints): updating endpoint status when detecting a change

* refactor(host): moved offline status panel from engine view to new host view

* fix(endpoints): missing endpoint update on ping from home view

* fix(api): rework EndpointUpdate operation

* refactor(offline): moved endpoint status to EndpointProvider and refactor the status-changed detection

* fix(offline): moved status detection to callback on views -> prevent displaying the offline message when endpoint is back online on view change

* fix(offline): offline message is now displayed online when browsing an offline endpoint

* fix(offline): sidebar updates correctly on endpoint status change

* fix(offline): offline panel not displayed and hidden on online mode

* refactor(offline): rework of OfflineMode management

* refactor(offline): extract information-panel for offlineMode into a component

* refactor(offline): remove redundant binding of informationPanel + endpointStatusInterceptor patter as service

* refactor(interceptors): moved interceptors pattern to service pattern

* feat(stacks): prevent inspection of a stack in offline mode

* feat(host): hide devices/disk panels in offline mode

* feat(host): disable browse action in offline mode

* refactor(home): remove comments

app/docker/components/datatables/containers-datatable/containersDatatable.js

@@ -10,6 +10,7 @@ angular.module('portainer.docker').component('containersDatatable', {
     reverseOrder: '<',
     showOwnershipColumn: '<',
     showHostColumn: '<',
-    showAddAction: '<'
+    showAddAction: '<',
+    offlineMode: '<'
   }
 });