Excessive calls of converter function when registering two message converters for same message type

[thomassedlmayer]

I created a minimal extension that just registers two message converters for the same message (to SceneUpdate and FrameTransform):

https://github.com/thomassedlmayer/lichtblick-extension-bug-demo

This results in excessive calls of the converter function for various frames (see timestamps in console logs) of the dataset when loading an mcap file (and setting the topic on visible!). This can be seen in the Developer Tool Console.

I added an example mcap file in the same demo repo.

[jdsika]

@laisspportugal this is a major problem