Added basic categorization functionality in the server & UI

src/app/settings/settings.component.scss

@@ -30,4 +30,55 @@
     margin-left: 15px;
     margin-bottom: 12px;
     bottom: 4px;
+}
+
+.category-list {
+    width: 500px;
+    max-width: 100%;
+    border: solid 1px #ccc;
+    min-height: 60px;
+    display: block;
+    // background: white;
+    border-radius: 4px;
+    overflow: hidden;
+}
+
+.category-box {
+    padding: 20px 10px;
+    border-bottom: solid 1px #ccc;
+    display: flex;
+    flex-direction: row;
+    align-items: center;
+    justify-content: space-between;
+    box-sizing: border-box;
+    cursor: move;
+    // background: white;
+    font-size: 14px;
+}
+
+.cdk-drag-preview {
+    box-sizing: border-box;
+    border-radius: 4px;
+    box-shadow: 0 5px 5px -3px rgba(0, 0, 0, 0.2),
+                0 8px 10px 1px rgba(0, 0, 0, 0.14),
+                0 3px 14px 2px rgba(0, 0, 0, 0.12);
+}
+
+.cdk-drag-animating {
+    transition: transform 250ms cubic-bezier(0, 0, 0.2, 1);
+}
+
+.category-box:last-child {
+    border: none;
+}
+
+.category-list.cdk-drop-list-dragging .category-box:not(.cdk-drag-placeholder) {
+    transition: transform 250ms cubic-bezier(0, 0, 0.2, 1);
+}
+
+.category-custom-placeholder {
+background: #ccc;
+border: dotted 3px #999;
+min-height: 60px;
+transition: transform 250ms cubic-bezier(0, 0, 0.2, 1);
 }