Offering mempool data to download

[crantini]

Hello,

Regarding https://github.com/citp/BlockSci/issues/332 Martin (@martinplattnr) writes:

Related idea: It might be helpful for (new) users to offer mempool data to download, as this is something that can't simply be re-created.

I had the same thought myself, actually. This would be helpful.

Every full-node has different a different mempool history of course, but a given timestamp could at least serve to answer, "we know that this transaction or block entered the network as early as this timestamp or earlier, but not later."

Moreover, the dataset file-size would be relatively small.

I myself have only very few historical mempool data; not enough to offer.

[maltemoeser]

I've added some thoughts in #332, sharing mempool data is difficult with the current implementation for the reasons laid out there as well as #2.