G3HWP load_data and load_file do not work interchangeably

[Katie Harrington]

While helping set up some data access for TSAT I'm noticing that the two different modes of operation for G3HWP don't work interchangeably. I can load a single file from HWP data but if I try to load via load_data I get an error that fields don't exist. Example below:

import datetime as dt
import sotodlib.hwp.g3thwp as g3thwp

fname = "/mnt/so1/data/ucsd-sat1/hk/16667/1666732499.g3"
cfg_file = "/mnt/so1/users/kmharrin/hwp_test/update_hwp_config.yaml"

hwp = g3thwp.G3tHWP(cfg_file)
## works
#data = hwp.load_file(fname)
## does not work
data = hwp.load_data( 
    start = dt.datetime(2022,10,25,21,14), 
    end = dt.datetime(2022,10,25,21,16),
)
solved = hwp.analyze(data)
print( solved["fast_time"].shape, solved["angle"].shape )