[Playground] [Hotfix] Remove autoscrolling from embedded editor

[miamihotline]

Removed autoscrolling from embedded editor, fixed GRPC getGraph errors in console, removed unnecessary requests from embedded iframe (hotfixes for the Beam Website bugs).

Thank you for your contribution! Follow this checklist to help us incorporate your contribution quickly and easily:

• Choose reviewer(s) and mention them in a comment (R: @username).
• Add a link to the appropriate issue in your description, if applicable. This will automatically link the pull request to the issue.
• Update CHANGES.md with noteworthy changes.
• If this contribution is large, please file an Apache Individual Contributor License Agreement.

See the Contributor Guide for more tips on how to make review process smoother.

To check the build health, please visit https://github.com/apache/beam/blob/master/.test-infra/BUILD_STATUS.md

GitHub Actions Tests Status (on master branch)

See CI.md for more information about GitHub Actions CI.

[asf-ci]

Can one of the admins verify this patch?

[asf-ci]

Can one of the admins verify this patch?

[pabloem]

thanks