fix: allow trailing slash after space in osnap rules

[Reinis-FRP]

Motivation

Some oSnap users have added trailing slash after their space id in rules parameter. We should not treat this as unsupported rules.

Summary

Adds optional trailing slash after space id in oSnap rules parsing regex.

Testing

Check a box to describe how you tested these changes and list the steps for reviewers to test.

• [ ] Ran end-to-end test, running the code as in production
• [x] New unit tests created
• [ ] Existing tests adequate, no new tests required
• [ ] All existing tests pass
• [ ] Untested

Issue(s)

Fixes #XXXX