Hemera/BlTouch fan bracket

Allows mounting of BLTouch to the front left of the extruder via the fan when using a more compact back plate for the ender3 along with a wrap around duct for the part cooling fan. (Mounting on the back of the motor is too far right and the probe cant see the left side of the bed)

Using backplate from the following thing as I've found it to be the stiffest solution hold the hemera in place.
https://www.thingiverse.com/thing:4030098
And using the following part cooling duct.
https://www.thingiverse.com/thing:4031637

Offsets are as follows (adjust Z as required)
NOZZLE_TO_PROBE_OFFSET { -28, -35, 0 }