V3 transaction policy for anti-pinning

[rustynail]

@instagibbs

Spec for HTLCs are identical to today, pretty much. Making those non-pinnable is out of scope for now as it would be a significantly larger spec change, with clear drawbacks. I think we can do better later without bothering spec people too much

@glozow Is this true? Why aren’t we figuring out this stuff now while the spec is developing? I thought V3 was supposed to fix all these pinning issues.