BME/BMP280: Don't publish data if no sensor is present & hotplugging

[chris-heo]

Is your feature request related to a problem? Please describe. Currently, when no BME/BMP280 is attached, each report cycle temperatures/humidity/pressure being 0 are published to MQTT

Describe the solution you'd like Only report, if data is actually available, init sensor when it's hot plugged and make the sensor address selectable via compiler flag

Describe alternatives you've considered I implemented it but am not as used to clone chungus repos & post pull requests, so find a patch attached :) BME280.diff.txt

Additional context Compiler flag in environment.ini e.g. '-DBME280_ADDR=0x77' can be used Limitation: if sensor are swapped in between reads (without an unsuccessful read), calibration data is not updated.