Update airgradient-pro.yaml to use variables and floats for c to f conversion

[robertsearle]

trafficstars

UNTESTED I am showing you a sneak preview

• Adding "WIFI SSID: $wifi_ssid" to boot
• Adding "Wifi: %.0fdbm" to combo screen
• Adding 32.05f to do rounding to one decimal
• using a variable for line0 and line1
• Moving 400 # 419 as of 2023-06 https://gml.noaa.gov/ccgg/trends/global.html to variable SENSE_AIR_S8_CO2_MIN