Any topic with multiple topic types causes image server to fail on desired topics

[rjb0026]

Description
If there are any active topics (publications or subscriptions) which have multiple message types associated with them, the web_video_server will bail out of its topic search early, sometimes before finding and establishing the stream for the desired topic, which may be valid.

• Library Version: ros2 branch (eb9af5f)
• ROS Version: Humble
• Platform / OS: Ubuntu 22.04

Steps To Reproduce

• publish two topics with the same name but differing types (e.g. /alpha)
• publish a different, valid image topic that is lexicographically greater than the topic above (e.g. /beta)
• Make a request to view the valid image topic

Expected Behavior
The valid image topic is still streamed.

Actual Behavior
The valid image topic is not streamed.

[sea-bass]

Closed by #146