feat: Automatic unit converter

[Mafeffe]

Some workout equipment only shows one unit of mass. If the preferred unit is not shown one would have to go out of the app to make the conversion, which is a hassle. I suggest something to make this easier for the user.

The next time the user is at the same machine, doing the same exercise, the previous used weight should show up (in the unit shown by the machine) to remind the user of the weight and reps. Otherwise the app would show kg for the exercise (for example), but the machine would be in lbs. This would again require a manual conversion by the user in order to find the previously used weight to set on the machine.

[andreped]

@Mafeffe Are you using Android or iOS, btw? I have seen some bugs on iOS lately, so I just wanted to know if I should prioritise this feature or the other bug first.

[Mafeffe]

Android. Haven't noticed any bugs except the one where you need to log an exercise as complete in order to save it.