Allow overriding speed setting per filament

[piotrb]

Is your feature request related to a problem? Please describe.
I seem to need to tweak my print profile speed setting per filament, some filaments are more finicky than others with the first layer speeds for example.

Describe the solution you'd like
I would love to have the ability to override some if not all of the speed options in the filament profiles.

Describe how it would work
Same as any of the other filament overrides

Describe alternatives you've considered
Right now I have to edit this in my profiles, I'm hoping not to have to keep editing those based on filament (otherwise what's the point of having a separate filament profile)

Additional context
Add any other context or paint drawing about the feature request here.

[supermerill]

#1223
#668