Preserve RabbitMQ topic names in queue stats

[abishekgiri]

Summary

• preserve the full topic name when RabbitMQ subscription keys are parsed for topic stats and topic listings
• switch the parsing logic to split from the right so topics containing colons are counted under the correct name
• add a regression test for a topic like orders:v1

Testing

• cargo test -p iii subscription_topic_preserves_topics_with_colons -- --nocapture

[vercel]

@abishekgiri is attempting to deploy a commit to the motia Team on Vercel.

A member of the Team first needs to authorize it.

[abishekgiri]

Updated RabbitMQ topic reporting so subscription keys are parsed from the right instead of the left. That keeps topic stats and list-topics output correct when the topic name itself contains colons, and it adds a regression test for that shape.