Enumerate parameters until TX Power entry is found, match
requested mW against TEXT_SELECT options, and write the
selected option index.
Added:
- str_contains_ci() for case-insensitive substring matching
- is_power_param() to detect power-related parameters
- match_power_option() to find mW in option strings
- 4 new tests: null port, frame roundtrip, success, not found
Ping sends DEVICE_PING frame and waits for DEVICE_INFO response.
Read sends PARAM_READ frame and waits for matching PARAM_ENTRY.
Both use cel_crsf_stream_feed() with a clock-based timeout loop.
Parse PARAM_ENTRY payload into cel_crsf_param struct. Handles
TEXT_SELECT with options string and UINT8/INT8 with min/max/default/
value fields. Respects hidden flag (bit 7 of type byte). Truncates
name and options to buffer limits.