feat(ai-chat): Add text field to describe manual SQL input field

Before, there was no direct description about the usage of the manual
SQL query input field. A plotly dash component was added with a more
precise description for the user.

app/app.py

@@ -203,6 +203,13 @@ def get_layout() -> html.Div:
                 "Direkte SQL-Abfrage",
                 style={"margin-left": "20px", "margin-top": "50px", "font-size": 24},
             ),  # SQL Header
+            html.Div(
+                (
+                    "Hier kann der ausgegebene SQL-Code getestet oder mit selbst"
+                    "geschriebenen Code verglichen werden."
+                ),
+                style={"margin-left": "20px", "font-weight": "bold", "font-size": "16px"},
+            ),
             dcc.Textarea(
                 id="sql-input-field",
                 value="(Microsoft) SQL-Abfrage eingeben...",