Peerstore interfaces should accept contexts

[guseggert]

The peerstore family of interfaces currently don't accept any Go contexts, despite performing IO. This means that, for example, the "pstoreds" package which implements a datastore-backed peerstore can't propagate contexts into the backing datastore. Example:

go-libp2p/p2p/host/peerstore/pstoreds/addr_book.go

Line 54 in 8c466ab

if err = write.Delete(context.TODO(), key); err == nil {

This means that the datastore can't respect context cancelations and any values stored in the context are also lost (ex. tracing metadata).

[marten-seemann]

Didn't we have a PR for that at some point?