Transformations: Fix field named Time matching all time fields

The byName and byNames matchers fall back to matching any time field when
the configured name is Time or time, so configs keep working after the
dataplane rename. The fallback also kicked in when the frame already had a
field with that name, so hiding `time` in Organize fields hid every time
field and Filter by name could not drop the other ones.

The fallback now only applies when no field in the frame has that name or
display name.

packages/grafana-data/src/transformations/matchers/nameMatcher.ts

@@ -115,8 +115,16 @@ function fieldNameFallback(fields: Set<string>) {
       );
     };
   } else if (fields.has('Time') || fields.has('time')) {
-    fallback = (field: Field, frame: DataFrame) => {
-      return frame.meta?.typeVersion == null && field.type === FieldType.time;
+    const timeNames = ['Time', 'time'].filter((name) => fields.has(name));
+    fallback = (field: Field, frame: DataFrame, allFrames: DataFrame[]) => {
+      return (
+        frame.meta?.typeVersion == null &&
+        field.type === FieldType.time &&
+        // A field that already carries the name is matched directly, so other time fields must not be pulled in
+        !frame.fields.some(
+          (f) => timeNames.includes(f.name) || timeNames.includes(getFieldDisplayName(f, frame, allFrames))
+        )
+      );
     };
   }