Implement the playwright/execute function

The playwright/execute function will use the following test reference format to execute tests:

{project}[/{directory}]#{specfile}[#{grep}],

where:

• {project} is mandatory
• {directory} is optional (for repos that hold more than one project)
• {specfile} is mandatory (it is a pattern)
• {grep} is optional

It should also:

• Take into account PLAYWRIGHT_EXTRA_OPTIONS environment variable
• Attach two reports: JUnit and HTML
• Maybe attach execution screenshots