Refactor Speed Indicator

[HoLuLuLu]

• Enlarge the size of current speed
• Relocate min/max speed under indicator line
• Add unit and unit name at the bottom of the card
• Use +/- Icons for buttons

Screenshots:

[HoLuLuLu]

It seems that I am using a newer version of flutter on my local PC (3.24.3) and the github action uses 3.19.5 which causes the build to fail because:

'MaterialStatePropertyAll' is deprecated and shouldn't be used. Use WidgetStatePropertyAll instead. Moved to the Widgets layer to make code available outside of Material. This feature was deprecated after v3.19.0-0.3.pre.

I use the recommended replacement WidgetStatePropertyAll which seems to not be included in the older flutter version used by the GH action. Maybe it's the better fix to update the flutter version in the github action instead of using a deprecated class which will be removed in more modern versions.

[hughesjs]

I've merged your fvm PR. Sorry I'm being a bit slow atm, I've just started a new job