[Feature Request] Replace current version by upgrading it

[JCKodel]

Is your feature request related to a problem? Please describe.

I'm always frustrated when a new Flutter version is released and I have to uninstall my global version, then install a new global with the new version (in addition, there is no --force or /y to make things easier).

Describe the solution you'd like

fvm upgrade should upgrade the current Flutter in use, replacing the current version.

It would be the same as:

fvm use 3.16.2 // this is my global
fvm remove 3.16.2
- yes
fvm global 3.16.3
- yes

I think this would make more sense only in the global version (I'm assuming everyone uses global as the current up-to-date flutter version, then have different old versions for old projects).

And, of course, add the --force flag so we can create some nice batch such as:

> copy con upgrade-flutter.cmd
@echo off
fvm use global
fvm upgrade --force
flutter doctor
^Z
>