Display MP used (or left) when doing Go to

[lmoureaux]

Is your feature request related to a problem? Please describe.
It's hard to know how many MP your unit will have left after walking somewhere. Basically you need to count tiles. The client has this info, so why not show it?

Describe the solution you'd like
Show something like "Go to: 0 turns, 2 2/9 MP" in the "unit actions" panel when in goto mode.

Describe alternatives you've considered

• Doing nothing.
• Show it on the map. It would take too much space.

Additional context
Requested by vic123 on Discord.