Fix gcode bug and add mqtt fan speed getters

[YOUR-WORST-TACO]

Description

Added needed fan speeds for a script I am writing, while testing found that the gcode execution was not functioning.

This PR seeks to solve the following issues:

• gcode codes not functioning properly
• add fan speed getters for part, auxiliary and chamber fans

[ohmdelta]

What printer and firmware version are u using

[YOUR-WORST-TACO]

X1C on 01.08.05.00

[ohmdelta]

Ok there's been a few changes to the firmware and the mqtt contract seems to have changed. We're probably not going to officially support 1.08 given the firmware lockdown. Think your changes are fine for older versions, will do some testing

[YOUR-WORST-TACO]

Does that support end at 1.08.05 or 1.08.02?

[ohmdelta]

lgtm

[ohmdelta]

Does that support end at 1.08.05 or 1.08.02?

as of right now we don't plan to support 1.08 officially, since it's like that firmware wont be allowed to be rolled back. It's likely a LAN mode in 1.08 might still work somewhat with this api. It does look unlikely that future firmware versions will be as open to interface with as 1.06 and below.

We're actually currently working through which firmware versions support certain functionalities - seems like M104 and M140 gcode via mqtt has been disabled since 1.07 for instance