Fix new transactions event payload

[nagdahimanshu]

What was the problem?

This PR resolves #1956

How was it solved?

• Format transactions before passing event payload to gateway
• Add configuration for heartbeatAckMaxWaitTime
• Update docs

How was it tested?

• Local
• Integration tests

[codecov]

Codecov Report

Merging #1957 (51687f7) into development (62f3626) will decrease coverage by 0.02%.
Report is 4 commits behind head on development.
The diff coverage is 42.85%.

Additional details and impacted files

@@               Coverage Diff               @@
##           development    #1957      +/-   ##
===============================================
- Coverage        67.99%   67.97%   -0.02%     
===============================================
  Files              299      299              
  Lines             5305     5309       +4     
  Branches           977      978       +1     
===============================================
+ Hits              3607     3609       +2     
- Misses            1698     1700       +2     

Files	Coverage Δ
services/blockchain-connector/config.js	100.00% <100.00%> (ø)
services/blockchain-indexer/config.js	100.00% <ø> (ø)
...chain-indexer/shared/dataService/business/index.js	100.00% <ø> (ø)
...ces/blockchain-indexer/shared/dataService/index.js	100.00% <ø> (ø)
services/export/config.js	100.00% <ø> (ø)
...ndexer/shared/dataService/business/transactions.js	28.20% <33.33%> (+0.13%)	⬆️

[sameersubudhi]

Works as expected 👍