fetch writeable calendars of user and display a dropdown in confirm dialog with list of calendars to choose for the event

templates/style.css

@@ -52,6 +52,17 @@
     overflow-wrap: anywhere;
 }
 
+.atocal-row select {
+    align-self: center;
+    width: 100%;
+    max-width: 280px;
+    padding: 6px 8px;
+    border: 1px solid var(--color-border);
+    border-radius: 6px;
+    background: var(--color-main-background);
+    color: var(--color-main-text);
+}
+
 .atocal-row .description {
     white-space: normal;
 }