feat: set internal property on http services

[kaylachun]

Motivation and Context

Transforms the 'x-internal' property in the oas document to internal. Related to a change that was requested for this pr https://github.com/stoplightio/platform-internal/pull/12208

Description

How Has This Been Tested?

Screenshot(s)/recordings(s)

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• [ ] This PR's code follows as closely as possible the coding style/guidelines of this project.
• [ ] I have added error reporting and followed the error reporting guidelines.
• [ ] I have added event tracking and followed the event tracking guidelines.
• [ ] I have updated any relevant documentation accordingly to reflect this PR's changes.
• [ ] I have added automated tests (unit/integration/e2e/other) to cover my changes.
• [ ] All new and existing tests pass locally (excluding flaky CI tests).

[stoplight-bot]

:tada: This PR is included in version 5.5.0 :tada:

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot :package::rocket: