Feature request to add a button for manual deploy when auto-build is disabled.

### Before opening, please confirm:

- [X] I have checked to see if my question is addressed in the [FAQ](https://github.com/aws-amplify/amplify-hosting/blob/master/FAQ.md).
- [X] I have [searched for duplicate or closed issues](https://github.com/aws-amplify/amplify-hosting/issues?q=is%3Aissue+).
- [X] I have read the guide for [submitting questions](https://github.com/aws-amplify/amplify-hosting/blob/master/CONTRIBUTING.md).
- [X] I have removed any sensitive information from my code snippets and submission.

### App Id

NO_APP

### AWS Region

us-east-1

### Amplify Hosting feature

Manual deploys, Webhooks

### Is your feature request related to a problem? Please describe:

When auto-build is disabled the only way to trigger a deployment manually is by creating a webhook and running the curl command. I envision a build now button which would do the same as auto deploy.

### Describe how you'd like this feature to work

When pressing the button the curl command will be executed and the build will be triggered and deployed.

The issue names no implementation files or tests. Start by reviewing the Manual deploys/Webhooks context, including FAQ.md and CONTRIBUTING.md, then compare the requested button with the existing curl-triggered deployment flow. Done means users can trigger and deploy a build from the interface when auto-build is disabled.

Written by the indexing model from the issue text.