chore: add types

[achingbrain]

Needs a bit of sanity checking as this datastore appears to require
Uint8Arrays as keys when every other datastore takes Keys as keys.

Does not type the tests because they use lots of libp2p primitives
and the types there need a bit of work still.

[hugomrdias]

LGTM, this datastore really shouldn’t be called datastore but as far as types goes looks good

[achingbrain]

Marked this as a draft as I'm going to integrate it with js-ipfs as a branch then circle back here and make sure the types reflect actual usage.

[vasco-santos]

Uint8Arrays as keys when every other datastore takes Keys as keys.

This should be consistent with the DHT API. Perhaps the docs are the problem here, however this also is part of a TieredDatastore

[achingbrain]

In IPFS we pass in the libp2p.pubsub property as the pubsub argument to this module's constructor, which has separate pubsub.on and pubsub.subscribe methods.

This module was passing the message handler as the second argument to pubsub.subscribe and not calling pubsub.on which means messages will never be received as subscribing and handling incoming messages are separate operations in libp2p.pubsub.

I've updated the code and tests to use the libp2p.pubsub interface as IPFS does at runtime.

[vasco-santos]

@achingbrain could we do the same thing in js-ipfs regarding the subscribe/on? I would like to get rid of https://github.com/libp2p/js-libp2p/blob/master/src/pubsub-adapter.js

[achingbrain]

could we do the same thing in js-ipfs regarding the subscribe/on?

Yes, I think so - it would be a case of doing something similar to that adapter in IPFS so we can keep the same external API.

[vasco-santos]

LGTM

FYI, I will be opening an issue to figure out the inconsistencies on datastore interface/dht for this repo , so that we track that