Update events indexing logic

[sameersubudhi]

What was the problem?

This PR resolves #1893

How was it solved?

• Explicitly index transactionID in the eventTopics table corresponding events where CCM ID exists with prefix in topics
• Add handling to deal with the topic prefix in the request params to fetch events
• Update gateway regex and documentation to allow user to specify transaction and CCM IDs with prefix

How was it tested?

Locally

[codecov]

Codecov Report

Merging #1897 (d12240f) into release/0.7.0 (3463ca5) will increase coverage by 0.01%.
The diff coverage is 75.00%.

@@                Coverage Diff                @@
##           release/0.7.0    #1897      +/-   ##
=================================================
+ Coverage          66.60%   66.62%   +0.01%     
=================================================
  Files                298      298              
  Lines               5214     5229      +15     
  Branches             935      941       +6     
=================================================
+ Hits                3473     3484      +11     
- Misses              1741     1745       +4     

Files	Coverage Δ
services/blockchain-indexer/shared/constants.js	53.65% <100.00%> (+1.15%)	⬆️
...vices/gateway/apis/http-version3/methods/events.js	100.00% <ø> (ø)
services/gateway/shared/regex.js	100.00% <100.00%> (ø)
...hain-indexer/shared/dataService/business/events.js	78.33% <69.23%> (-1.11%)	⬇️

[nagdahimanshu]

LGTM 👍