rust: Add ws-stream-mcap example

[gasmith]

To play with the time messages, I wrote a little example to stream mcap files over a websocket. Might also be useful for performance testing against real data.

To use:

$ cargo run -p example-ws-stream-mcap --release -- --file ~/Downloads/example-014-ugv-ds.mcap --loop
[2025-02-07T18:32:26Z INFO  foxglove::runtime] Creating tokio runtime
[2025-02-07T18:32:26Z INFO  ws_stream_mcap] Loading mcap summary
[2025-02-07T18:32:26Z INFO  ws_stream_mcap] Waiting for client
[2025-02-07T18:32:29Z DEBUG tungstenite::handshake::server] Server handshake done.
[2025-02-07T18:32:29Z INFO  foxglove::websocket] Registered client 127.0.0.1:40132 advertising 38 channels
[2025-02-07T18:32:29Z INFO  foxglove::websocket] Advertised channel /os1_cloud_node/points with id 12 to client 127.0.0.1:40132
[2025-02-07T18:32:29Z INFO  foxglove::websocket] Advertised channel /downsampled_accumulated_points with id 6 to client 127.0.0.1:40132
[2025-02-07T18:32:29Z INFO  foxglove::websocket] Advertised channel /os1_cloud_node/points_downsampled with id 37 to client 127.0.0.1:40132
[2025-02-07T18:32:29Z INFO  foxglove::websocket] Advertised channel /right_drive/status/battery_voltage with id 16 to client 127.0.0.1:40132
...
[2025-02-07T18:32:31Z INFO  ws_stream_mcap] Starting stream
^C[2025-02-07T18:32:56Z INFO  foxglove::websocket] Shutting down
[2025-02-07T18:32:56Z INFO  foxglove::websocket] Unadvertised channel with id 10 to client 127.0.0.1:40132
[2025-02-07T18:32:56Z INFO  foxglove::websocket] Unadvertised channel with id 7 to client 127.0.0.1:40132
...

[amacneil]

Neat! Not sure if you've seen this prior art mcap-play in this repo, but it's great to have a rust example.

https://github.com/foxglove/ws-protocol/tree/main/typescript/ws-protocol-examples

[bryfox]

Looks good; works well.

Note usage in PR description is out of date.