loop control flow label "elision" inlay hints

[Veykril]

Similar to lifetime elision hints, we should have label hints for control flow constructs.

That is for,

loop {
    loop: {
        break;
    }
    continue;
}

we should have the following hints

'0: loop {
    '1: loop {
        break '1;
    }
    continue '0;
}

For configs, enabled, disabled and a third option for only showing it in nested loop contexts would make sense I think

[Veykril]

This is blocked on having loop resolution happen in body lowering cc #14498