add friendly_name method [DEVINFRA-1045]

[adrian-kong]

Add friendly_name method which trims out keywords

{
        "TRACKING": "TRK",
        "MEASUREMENT": "MEAS",
        "INDEX": "IDX",
        "NETWORK": "NET",
        "EPHEMERIS": "EPH",
        "_": " "
}

and 
"^MSG_"
"_GNSS$"

[silverjam]

To statisfy SonarCloud let's add a simple unit test to Java that asserts that the friend name for each message is not empty.

[notoriaga]

One comment about possibly adding fn friendly_name(&self) -> &'static str to SbpMessage so you can directly fetch the friendly name, but that can be done later so LGTM!