fix(mail(js)): unselect all messages when changing mailbox

Fixes #4970
Fixes #5148

UI/WebServerResources/js/Mailer/Mailbox.service.js

@@ -302,6 +302,17 @@
     return this.$selectedMessages().length;
   };
 
+  /**
+   * @function $unselectMessages
+   * @memberof Mailbox.prototype
+   * @desc Unselect all messages.
+   */
+  Mailbox.prototype.$unselectMessages = function() {
+    _.forEach(this.$selectedMessages(), function(message) {
+      message.selected = false;
+    });
+  };
+
   /**
    * @function isSelectedMessage
    * @memberof Mailbox.prototype

UI/WebServerResources/js/Mailer/Mailer.app.js

@@ -255,11 +255,13 @@
     if (Mailbox.$virtualMode)
       return [];
 
-    if (stateMailbox)
+    if (stateMailbox) {
+      stateMailbox.$unselectMessages();
       promise = stateMailbox.$filter().catch(function() {
         // Mailbox not found
         return $q.reject('Mailbox not found');
       });
+    }
     else
       promise = $q.reject("Mailbox doesn't exist");