batches: make it clearer from `/edit` when there's an active execution

Created by: courier-new

Potentially closes https://github.com/sourcegraph/sourcegraph/issues/37076. 🙂

• Uses history.replace to route to the execution page when you submit a batch spec for execution, so that using the browser back button doesn't take you back to /edit
• Shows a warning from /edit if there's an active execution for the latest batch spec

Demo:

https://user-images.githubusercontent.com/8942601/173489556-fe414c5d-e728-4ba8-b2d9-adcffd83a9dc.mov

Test plan

Tested workflow manually, in attached video above.

App preview:

• Web
• Storybook

Check out the client app preview documentation to learn more.