Cable client tweaks

to display debug data, use as following:

DEBUG="*" <command> -- show all de...

this naming makes it congruous with the post/info key 'name'

in this slightly large commit we do a few different but related things.
all these changes are ai...

deduplicated a bit of code by refactoring repetitive statements

resolveHashes purpose is for getting json from indexes and buffers and
returning it to users of ...

implement safeguards at multiple levels so that we check each incoming
post, or hashes to reques...

this commit adds unit tests for exercising the links functionality. as
part of implementing the ...

this commit fixes the little inconsistencies that arise when writing
something all in one go wit...

also patches index.js to return early if we don't have any hashes to
request

also here: fixed a big typo & refactored tests to improve their robustness,
and started revampin...

per the spec rev 2023-04, a user may join a explicitly (already handled)
and implicitly (added i...

add tests that make sure that the behaviour for a channel state request
with future = 1 is corre...

this commit makes a substantial change to the way deletes are handled in
that the behaviour for ...

instead of using a temporary object, seen = {}, we now have a column
that we query before decidi...

we now filter out query results that fail to find a match for one of our
passed in keys

regular key scheme is: `<channel>!<pubkeyHex>: 0|1`

sentinel key scheme is: `<channel>!<'x'.rep...

augments handleResponse, handleRequest with done callbacks to facilitate
testing, and further fo...