Per Exercise Weight Units

[LiamMorrow]

Currently LiftLog supports a global "Units" setting, which switches between using pounds and kilograms. This doesn't actually affect anything other than the suffix when we display weight. (i.e. If you save a session with an exercise which had 10Kg, if you switch the app to use pounds, it will say the exercise was 10Lb).

This covers a lot of the cases, but many gyms outside of the US use Kilograms for freeweights, then pounds for some machines. This means you either have to convert to kilograms in your head, or just write the pounds as kilograms. For the record, writing the machine pound weight as if they were kilograms is what I have been doing for the past 2 years of using this app, without doing any conversion. Since I only care that I am progressively overloading, the actual weight doesn't matter if I am using the same machine.

It would be NICE however if weights were stored with their units, and potentially allow for a unit setting on a per exercise level.

This feature would mean that anywhere we sum up the weights (stats, session totals), we would need to be units aware, and convert them to the app's main unit. Additionally in the CSV export added by #316