feat(vMix): support browser source url in vMix

[ianshade]

About the Contributor

This pull request is posted on behalf of TV 2 Norge

Type of Contribution

This is a:

Feature

Current Behavior

URL of the Browser input in vMix can not be controlled by TSR

New Behavior

URL of the Browser input in vMix can be controlled using the added url property of TimelineContentVMixInput.
There is a limitation: The URL can't be read via the API, therefore (re)start or reconnection may issue a BrowserNavigate command even if the URL is already as expected

Testing Instructions

1. Add a Browser input to vMix
2. Create a mapping and a timeline object as shown in the 'supports url' test case
3. Verify if the URL has changed when the timeline object started

Other Information

Status

• PR is ready to be reviewed.
• The functionality has been tested by the author.
• Relevant unit tests has been added / updated.
• Relevant documentation (code comments, system documentation) has been added / updated.