use appId for selector

[circlecube]

Proposed changes

Tweak the new product page test to be compatible with other brand plugins using the appId for element selector. The test currently passes for bluehost, but fails for other brand plugins.

Type of Change

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation Update (if none of the other choices apply)

Checklist

• I have read the CONTRIBUTING doc
• Linting and tests pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)

Further comments

[circlecube]

Merging this as it fixes module-based tests to work in all brands, but to get all passing tests in brand plugins they each need to update the marketplace integration (bluehost is complete).