[experiment] Do we need to store blocks ourself?

[patrick-ogrady]

It should be required to only store the last accepted block + any pre-proposervm blocks (genesis) on disk. The rest should be stored on our behalf by the proposervm in avalanchego (and served to anyone that wants them).

Invariant: we never serve inner blocks to peers, only wrapped blocks?

[patrick-ogrady]

Warning: This may make an eventual conversion to more pluggable leadering mechanisms more complex

[patrick-ogrady]

This may not work if any block is accepted that doesn't have a proposervm wrapper (need to still store non-context blocks).

Even if there is no proposer, will always be wrapped.