Helium sketch limited to US, fails on many platforms

[terrillmoore]

The new #647 CI framework reveals that the Helium sketch fails many tests Needs attention.

STM32:

Error: helium-us915 for board mcci_catena_4610 region us915 radio sx1276: compile failed
Error: helium-us915 for board mcci_catena_4610 region au915 radio sx1276: compile failed
Error: helium-us915 for board mcci_catena_4612 region us915 radio sx1276: compile failed
Error: helium-us915 for board mcci_catena_4612 region au915 radio sx1276: compile failed
Error: helium-us915 for board mcci_catena_4618 region us915 radio sx1276: compile failed
Error: helium-us915 for board mcci_catena_4618 region au915 radio sx1276: compile failed
Error: helium-us915 for board mcci_catena_4630 region us915 radio sx1276: compile failed
Error: helium-us915 for board mcci_catena_4630 region au915 radio sx1276: compile failed
Error: helium-us915 for board mcci_catena_4801 region us915 radio sx1276: compile failed
Error: helium-us915 for board mcci_catena_4801 region au915 radio sx1276: compile failed
Error: helium-us915 for board mcci_catena_4802 region us915 radio sx1276: compile failed
Error: helium-us915 for board mcci_catena_4802 region au915 radio sx1276: compile failed

SAMD: ok (is it compiling?)

ESP32:

Error: helium-us915 for board heltec_wifi_lora_32 region us915 radio sx1276: compile failed
Error: helium-us915 for board heltec_wifi_lora_32 region au915 radio sx1276: compile failed

AVR: ok (is it compiling?)

[terrillmoore]

I fixed the sketch to use the built-in pinmaps and be relaxed about whether it recognizes the BSP. This was committed in 662c63b. At the same time, I renamed it to helium-otaa, and added it to CI for all regions (066d125).