Add limiter

[mossmann]

We want to limit input power to somewhere between 10 dBm and 20 dBm.

Initial test results suggest we should be able to achieve this with a PIN-Schottky limiter: https://github.com/greatscottgadgets/lab-notes/tree/main/rf-testing/2022-04-24-limiter-test

The BAR9002ELSE6327XTSA1/BAT2402LSE6327XTSA1 solution tested there would be a good place to start, but we would like to test more options to see if we can achieve better results and/or reduce cost.

We'll also need to test with input signals well above 20 dBm to determine the external absolute maximum input power we will be able to tolerate.