SNIP sandboxing fix

[pondersome]

SNIP 3_10_00 release – released June 05 2023 introduced quick bans and sandboxing.

rtk2go is now enforcing a policy where server requests coming in at greater than 1hz can trigger the ban. The ntrip_client codebase communicates with the server at 10hz (hard-coded) for rtcm requests and at whatever the message rate is for NMEA messages. This will trigger sandboxing.

I have a fix that allows the user to specify the NTRIP server communication rate through a parameter. Both rtcm requests and nmea sentences are published at ntrip_server_hz. It's no longer necessary to use topic_tools throttle nodes. Setting the parameter to 1 has resolved the problem for me:

https://github.com/pondersome/ntrip_client/tree/feature/ros2_ntrip_rate_control

The fix only addresses ROS2. I'll submit a PR.