Dashboard Migration: Add missing e2e selectors to some components

[axelavargas]

Context: Dashboard: POC to run existing e2e with dashboardScene feature toggle #84598

To run the existing e2e tests on Grafana core, we need to make sure we have all the data-testid in the components used there.

• [x] Add testid to tile in SceneGridRow
• [x] VizPanelMenu

Note: I am keeping the PR on draft to add the missing data-testid in one go :)

📦 Published PR as canary version: 4.12.3--canary.648.8818501335.0

:sparkles: Test out this PR locally via: ```bash npm install @grafana/scenes@4.12.3--canary.648.8818501335.0 # or yarn add @grafana/scenes@4.12.3--canary.648.8818501335.0 ```

[grafanabot]

:rocket: PR was released in v4.12.3 :rocket: