feat: show all fan and pin values as percentages

[pedrolamas]

Ideally, limited scale values in the front-end should be presented as a percentage instead of the Klipper value - that is for config and console purposes.

The changes in this pull request are as follows:

• non-controllable (read-only) fans and output pins will show "Off" when value is 0, otherwise presents the value on a scale of 0% to 100%.
• controllable pwm output-pins will always present the value on a scale of 0% to 100%.

Before

After

Partial test config used for the above:

[heater_fan heater_fan]
pin: PD4
off_below: 0.2
shutdown_speed: 0.0
max_power: 0.6
fan_speed: 0.85

[output_pin test_pwm_pin]
pin: PD7
pwm: True
value: 0.6
scale: 0.8
cycle_time: 0.1