altosui: Start adding code to write csv files from eeprom/telem files

altosui: Start adding code to write csv files from eeprom/telem files

This is a start to code which can write out a csv file full of flight
data from either an eeprom or telem input file. It's not hooked up,
but the restructuring necessary is finished and the output is started.

Signed-off-by: Keith Packard <keithp@keithp.com>