If a print has been saved to RAM such as during a filament runout,
do not overwrite these saved values if a sudden
power panic appears.
Additionally, change the saved types to be the same as power panic when saving to RAM:
- Bed target temperature is uint8_t (0 to 255) instead of float
- Extruder target temperature is uint16_t instead of float
Doing this change allows us to re-use the same global variables and
avoid creating local variables during power panic.
Change in memory:
Flash: -246 bytes
SRAM: -5 bytes