This adds the ability to enable "optimistic provide" to the default
DHT client, which enables faster provides and reprovides.
For more information about optimistic provide, see:
https://protocollabs.notion.site/Optimistic-Provide-2c79745820fa45649d48de038516b814
Note that this feature only works when using non-custom router
types. This does not include the ability to enable optimistic provide
on custom routers for now, to minimize the footprint of this
experimental feature. We intend on continuing to test this and improve
the UX, which may or may not involve adding configuration for it to
custom routers. We also plan on refactoring/redesigning custom routers
more broadly so I don't want this to add more effort for maintainers
and confusion for users.
