Refactor ID mapping

[flx42]

Preliminary work for #239

[cyphar]

Please run gofmt on the changed files -- that's what's causing the CI to fail. It would also be nice if we could put the new code inside utils_ux.go (and possibly making it follow the existing uxImage style where it is automatically applied based on the command type, thought I don't think we can abuse the categories for this...).

[flx42]

Moved the command decorator to utils_ux.go and renamed it uxRemap.
Should we also move the ID parsing function to utils_ux.go though? This doesn't seem really right for me.

I don't think we can reuse the category mechanism for this since it can't be chained in its current form, the decorator approach can.

[cyphar]

Should we also move the ID parsing function to utils_ux.go though? This doesn't seem really right for me.

No, but we could put it into utils.go. However, maybe we should use the same ctx.App.Metadata trick that we use for other parsed options. The downside is that you'd need to stuff in a MapOptions struct into it. This is something I could look into refactoring later if it makes it easier for you.

I don't think we can reuse the category mechanism for this since it can't be chained in its current form, the decorator approach can.

I will try to figure out a work-around for this after we merge it as well (since it's more of a maintenance thing than anything else).

[flx42]

It's now in utils.go.
For the rest, I agree that it might be worth it to postpone to a separate PR. It doesn't sound pretty to shove a struct inside a metadata string (do we really want to json encode/decode here?).

[cyphar]

Sure, that's fine (though for reference the Metadata map is of interface{}, not string). Will review in a bit.

[cyphar]

LGTM.