Fix altitude unit problems

[emahon]

Apparently indicator endpoint -> altitude_hour (and presumably altitude_minute and altitude_10k as well) shows different units depending on the plane:

P-36A: Feet F-5C: Feet Z.1007 bis serie 3: Meters G.91 R/4: Feet (???????)

Need to resolve so we get altitude for energy calculations in consistent units.

Potential solutions:

• Pull data from a different endpoint that has consistent units (something in state endpoint?)
• Add a toggle switch allowing user to pick feet or meters for altitude based on what they see in game
• Dig through plane config files and compile a list of plane -> units to use

[emahon]

Went with solution 1 - got everything from the state endpoint, which is always in meters for altitude and km/h for TAS. This comes at the cost of only getting these values as integers, so some precision is lost, but I think it's acceptable.

[emahon]

Is it possible to extract the units from the HUD info somehow? maybe at start of match could compare to the state endpoint and determine unit by the factor? This would give us the precision and accuracy