Add peers to lookup ancestors

[dapplion]

Description

If a peer claims to have imported block A, and we have a parent chain of blocks with block A as tip, then the peer must know about all those ancestor blocks.

We should insert the peer into all those lookups, not just the lookup of block A.

Version

unstable

[1010adigupta]

would like to work on this

[dapplion]

We are currently debugging the logic that this issue depends on. If you don't mind @1010adigupta I'll take this one

[1010adigupta]

okay , I will try to learn from your pr