Signal bit length checks fail for several production DBCs

[nyurik]

There are several test files that fail to generate code due to bit length validations. These errors are not caught by the opendbc project, so it is uncertain if it is a data issue or if dbc-codegen needs to treat some cases more leniently.

FORD_CADS_64

• opendbc/FORD_CADS_64.dbc

write message `MRR_Detection_022`
write signal impl `CAN_DET_SUPER_RES_TARGET_22_03`
signal starts at 207, but message is only 192 bits

mazda_3_2019

• opendbc/mazda_3_2019.dbc

write message `CAM_KEEP_ALIVE_1`
write signal impl `NEW_SIGNAL_4`
signal ends at 78, but message is only 64 bits

mazda_2017

• opendbc/mazda_2017.dbc

write message `HVAC`
write signal impl `NEW_SIGNAL_4`
signal ends at 68, but message is only 64 bits

vw_pq

• opendbc/vw_pq.dbc

write message `Lenkhilfe_1`
write signal impl `LH1_EPS_Diagmode`
signal ends at 17, but message is only 16 bits

hyundai/hyundai_palisade_2023

• opendbc/generator/hyundai/hyundai_palisade_2023.dbc

write message `FRT_RADAR11`
write signal impl `BYTE2`
signal ends at 24, but message is only 16 bits

dbc-cantools/bad_message_length (part of OxiBUS test suit)

• dbc-cantools/bad_message_length.dbc

write message `Message1`
write signal impl `Signal1`
signal ends at 9, but message is only 8 bits