Performance improvement

[jrwbabylonlab]

• The bootstrap is querying block events one by one, we can improve the speed by utilising the goroutines by doing multiple queries at the same time
• same db query being called multiple times within a single event execution. e.g GetBTCDelegationByStakingTxHash being called inside validateBTCDelegationInclusionProofReceivedEvent which then being called again
  by processBTCDelegationInclusionProofReceivedEvent. a recommendation is doing request level caching. i.e cache once per execution