Determining L-Band operating region

[cturvey]

Subject of the issue

US Facet L-Band units being moved to UK/EU theater, the auto-set operation may overly cumbersome and opaque.

https://portal.u-blox.com/s/question/0D5Oj00000E3f9tKAB/pointperfect-perfomance-in-the-uk

https://github.com/sparkfun/SparkFun_RTK_Firmware/blob/main/Firmware/RTK_Surveyor/menuPP.ino#L1154

Looks to make a determination when beginLBand() is called from setup(), when device starts

https://github.com/sparkfun/SparkFun_RTK_Firmware/blob/ad3899b609e2d2b3f88d74b7b3c3411c0b72834f/Firmware/RTK_Surveyor/RTK_Surveyor.ino#L936

It needs a position fix to see which Inmarsat shadow it's in, and from there it selects the L-Band frequency. So you'll need to have a fix, and then restart the Facet whilst not resetting the receiver .

One of the older screen shots showed "Configure LBand" but I think that's been deprecated, and now it's "Configure PointPerfect", but there really needs to be a method to report the frequency, and update that based on the location when the menuPointPerfect() is triggered, or a manual method is provided for.