feat(rln-relay): 0.16.0 release

[rymnc]

Problem

This is to keep track of the rln-relay features to be ready for integration in the next nwaku release 0.16.0.

• Key store for RLN credential management (@s1fr0)

  • 17/WAKU-RLN-RELAY: File format to backup credentials? vacp2p/rfc#543
  • feat: store contract address in rlnCredentials.txt #1238
  • feat(rln): How to securely store RLN credentials cross-client #1278

• Fix message validation (@rymnc)

  • chore(rln-relay): update message validation  #1451
  • chore(rln-relay): bump zerokit and update ffi #1571

• Refactoring to improve rln-relay interface (@rymnc)

  • chore(rln-relay): Separation of group registration from rln-relay mounting process #1369
  • chore(rln-relay): fix minor issues (fn naming etc) #1487
  • use rln static library to minimize dependency on resources
    • feat(rln): package rln w/ resources into a static lib vacp2p/zerokit#118
    • feat(rln-relay): use precompiled resources w/ rln #1578

• Address outstanding issues with rln-contract and update waku-rln-relay's contract interface (@rymnc)

  • Modernize repo and fix deployment process vacp2p/rln-contract#15
  • Develop a GroupStorage contract  vacp2p/rln-contract#16

There are a couple of other low-hanging fruits which we can attempt in case the above list is completed earlier than the deadline.

Acceptance criteria

Getting the listed features ready and tested by the indicated deadline below.
Making sure there is no regression regarding the added features on the waku v2 fleets.

Deadline

March 8, 2023 (one week prior to the next release date)

cc: @jm-clius @s1fr0

[jm-clius]

Seems like this issue is very close to having all tasks completed. Should we carry those over to a next release and close, @rymnc ?

[rymnc]

Yes, was planning to do that after the 0.16.0 release!
will do it soon