Allow forwarding X11 to VM

[jordemort]

This allows people who have XQuartz installed to easily install and run X11 applications inside lima.

This is a nicer replacement for #875 - it adds two new settings to the ssh section of the template - forwardX11 and forwardX11Trusted correspond to the similarly-named ssh options, like forwardAgent does.

[jordemort]

It's unclear to me why the alpine test is failing here

[jordemort]

Looks like the alpine test cleared itself up somehow? I did not intervene.

[AkihiroSuda]

Looks like the alpine test cleared itself up somehow? I did not intervene.

I restarted the CI and it became green

[jandubois]

I'm not keen on adding every SSH option individually to lima.yaml, but I guess having a generic mechanism to provide "any" additional options might be error-prone.

So, I'm not sure what I'm saying. I guess I'm fine with adding these 2 options, but if the list continues to grow, then this might become unmaintainable.

I'm going to approve this PR based on the code changes, but will leave the merging to @AkihiroSuda

[jordemort]

@jandubois Yeah it could get ugly if there are too many more of these. I could whip up an "arbitrary SSH option" PR if you'd rather; I think it could be done at least semi-safely, by filtering out the ones limactl cares about for its own use.

On the other hand, for at least my personal use case, I can't see wanting much else beyond this. The UNIX socket forwarding stuff that was added covers the rest of the weird stuff I want to do (GPG agent, PulseAudio, etc)

[AkihiroSuda]

Thanks

[AkihiroSuda]

"arbitrary SSH option"

SGTM, but this PR also makes sense