Fix mainnet genesis block indexing

[sameersubudhi]

What was the problem?

This PR resolves #1962

How was it solved?

• Add safety checks to ensure that API client healthcheck is only triggered after both the nodes are synced and genesis block is downloaded
• Use event-based liveness checks only for IPC clients
• Update the NATS server max payload config
• Update max_memory limits in pm2 config files

How was it tested?

• Locally against the mainnet
  • Follow "Steps to reproduce" from Fix mainnet genesis block indexing #1962
• Against the testnet, both locally and on the server

[codecov]

Codecov Report

Merging #1963 (76b6486) into development (46e603c) will not change coverage.
Report is 4 commits behind head on development.
The diff coverage is n/a.

Additional details and impacted files

@@             Coverage Diff              @@
##           development    #1963   +/-   ##
============================================
  Coverage        68.03%   68.03%           
============================================
  Files              299      299           
  Lines             5309     5309           
  Branches           978      978           
============================================
  Hits              3612     3612           
  Misses            1697     1697           

see 3 files with indirect coverage changes

[nagdahimanshu]

LGTM 👍