Update styles and add task priority feature

- Changed border color from #eee to #cdcdcd in various CSS files including dropzone, mapplic, summernote, grid, and select2 to enhance UI consistency.
- Added a new task priority selection feature in the task popup, allowing users to change the priority of tasks dynamically via AJAX.
- Implemented AJAX functionality to handle task priority changes and update the task list accordingly.

libraries/framework/skin/base/pages.less

@@ -262,7 +262,7 @@ body.messages-page {
 	.message-menu {
 	  padding: 10px 15px;
 	  background-color: #FFF;
-	  border-bottom: 1px solid #EEE;
+	  border-bottom: 1px solid #cdcdcd;
 	}
 
 	// message compose btn
@@ -350,7 +350,7 @@ body.messages-page {
     }
     .dockmodal-body .quick-compose-form input.form-control {
         border: 0;
-        border-bottom: 1px solid #EEE;
+        border-bottom: 1px solid #cdcdcd;
     }
     .dockmodal-body .quick-compose-form .note-editor .note-editable {
         background: #f9f9f9;
@@ -565,8 +565,8 @@ body.invoice-page {
 	 // Summary table last row 
 	#invoice-summary tbody tr:last-child td {
 	  background: #fafafa;
-	  border-top: 1px solid #EEE;
-	  border-bottom: 1px solid #EEE;
+	  border-top: 1px solid #cdcdcd;
+	  border-bottom: 1px solid #cdcdcd;
 	  height: 24px;
 	  line-height: 24px;
 	}
@@ -886,7 +886,7 @@ body.error-page {
 		padding: 10px 20px;
 		border: 0;
 		font-size: 16px;
-		border: 1px solid #EEE;
+		border: 1px solid #cdcdcd;
 		border-left: 5px solid @brand-primary;
 		background: #FBFBFB;
 	}