Creator pairing groups refactor

What does this MR do?

• removed the nesting <ul> -> <div> -> <ul> for sake of semantic HTML;
• changes content-list with group-list to prevent overriding content-list styles locally for groups (for example, for text max-width)

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done