sensor_combined cleanup: remove many unneeded fields

Decreases the message size from 780 to 280 bytes.
In particular, all modules using sensor_combined must use the integral now.
The sensor value can easily be reconstructed by dividing with dt.

Voters now need to be moved into sensors module, because error count and
priority is removed from the topic.

Any module that requires additional data from a sensor can subscribe to
the raw sensor topics.

At two places, values are set to zero instead of subscribing to the raw
sensors (with the assumption that no one reads them):
- mavlink mavlink_highres_imu_t::abs_pressure
- sdlog2: sensor temperatures