Add channels preferences management

src/channels/actions/UpdateChannelAdminGroup.js

src/channels/actions/UpdatePreferences.js

.../AddGroupToChannelComponent/AddGroupToChannelComponent.js

...nnels/components/ChannelMembers/ChannelGroupsComponent.js

...nnels/components/ChannelsFilterMenu/ChannelsFilterMenu.js

src/channels/components/ChannelsList/ChannelsList.js

.../components/EditChannelComponent/EditChannelComponent.css

...s/components/EditChannelComponent/EditChannelComponent.js

...components/EditChannelComponent/EditChannelComponent.scss

...elAdminGroupComponent/UpdateChannelAdminGroupComponent.js

...ages/ChannelGlobalPreferences/ChannelGlobalPreferences.js

src/channels/pages/CreateChannelPage/CreateChannelPage.css

src/channels/pages/CreateChannelPage/CreateChannelPage.js

src/channels/pages/CreateChannelPage/CreateChannelPage.scss

src/channels/pages/EditChannelPage/EditChannelPage.js

src/common/pages/MainPage/MainPage.js

...tratorNotificationsList/AdministratorNotificationsList.js

...ications/components/NotificationsList/NotificationList.js

...earchNotificationComponent/SearchNotificationComponent.js

...ts/SendNotificationComponent/SendNotificationComponent.js