rpc: Add `TotalGasUsed` to `block_results` response (#6615)

Closes #6551 

Simple PR to add the total gas used in the block by adding the gas used in all the transactions. 
This adds a `TotalGasUsed` field to `coretypes.ResultBlockResults`.

Its my first PR to the repo so let me know if there is anything I am missing!

@fedekunze In case you want to take a look

CHANGELOG_PENDING.md

@@ -126,6 +126,7 @@ Friendly reminder: We have a [bug bounty program](https://hackerone.com/tendermi
 - [p2p/pex] \#6509 Improve addrBook.hash performance (@cuonglm)
 - [consensus/metrics] \#6549 Change block_size gauge to a histogram for better observability over time (@marbar3778)
 - [statesync] \#6587 Increase chunk priority and re-request chunks that don't arrive (@cmwaters)
+- [rpc] \#6615 Add TotalGasUsed to block_results response (@crypto-facs)
 
 ### BUG FIXES
 
@@ -134,5 +135,5 @@ Friendly reminder: We have a [bug bounty program](https://hackerone.com/tendermi
 - [blockchain/v1] \#5711 Fix deadlock (@melekes)
 - [evidence] \#6375 Fix bug with inconsistent LightClientAttackEvidence hashing (cmwaters)
 - [rpc] \#6507 fix RPC client doesn't handle url's without ports (@JayT106)
-- [statesync] \#6463 Adds Reverse Sync feature to fetch historical light blocks after state sync in order to verify any evidence (@cmwaters) 
+- [statesync] \#6463 Adds Reverse Sync feature to fetch historical light blocks after state sync in order to verify any evidence (@cmwaters)
 - [fastsync] \#6590 Update the metrics during fast-sync (@JayT106)

rpc/core/blocks.go

@@ -161,9 +161,15 @@ func (env *Environment) BlockResults(ctx *rpctypes.Context, heightPtr *int64) (*
 		return nil, err
 	}
 
+	var totalGasUsed int64
+	for _, tx := range results.GetDeliverTxs() {
+		totalGasUsed += tx.GetGasUsed()
+	}
+
 	return &ctypes.ResultBlockResults{
 		Height:                height,
 		TxsResults:            results.DeliverTxs,
+		TotalGasUsed:          totalGasUsed,
 		BeginBlockEvents:      results.BeginBlock.Events,
 		EndBlockEvents:        results.EndBlock.Events,
 		ValidatorUpdates:      results.EndBlock.ValidatorUpdates,

rpc/core/blocks_test.go

@@ -72,9 +72,9 @@ func TestBlockchainInfo(t *testing.T) {
 func TestBlockResults(t *testing.T) {
 	results := &tmstate.ABCIResponses{
 		DeliverTxs: []*abci.ResponseDeliverTx{
-			{Code: 0, Data: []byte{0x01}, Log: "ok"},
-			{Code: 0, Data: []byte{0x02}, Log: "ok"},
-			{Code: 1, Log: "not ok"},
+			{Code: 0, Data: []byte{0x01}, Log: "ok", GasUsed: 10},
+			{Code: 0, Data: []byte{0x02}, Log: "ok", GasUsed: 5},
+			{Code: 1, Log: "not ok", GasUsed: 0},
 		},
 		EndBlock:   &abci.ResponseEndBlock{},
 		BeginBlock: &abci.ResponseBeginBlock{},
@@ -97,6 +97,7 @@ func TestBlockResults(t *testing.T) {
 		{100, false, &ctypes.ResultBlockResults{
 			Height:                100,
 			TxsResults:            results.DeliverTxs,
+			TotalGasUsed:          15,
 			BeginBlockEvents:      results.BeginBlock.Events,
 			EndBlockEvents:        results.EndBlock.Events,
 			ValidatorUpdates:      results.EndBlock.ValidatorUpdates,

rpc/core/types/responses.go

@@ -62,6 +62,7 @@ type ResultCommit struct {
 type ResultBlockResults struct {
 	Height                int64                     `json:"height"`
 	TxsResults            []*abci.ResponseDeliverTx `json:"txs_results"`
+	TotalGasUsed          int64                     `json:"total_gas_used"`
 	BeginBlockEvents      []abci.Event              `json:"begin_block_events"`
 	EndBlockEvents        []abci.Event              `json:"end_block_events"`
 	ValidatorUpdates      []abci.ValidatorUpdate    `json:"validator_updates"`

rpc/openapi/openapi.yaml

@@ -1666,6 +1666,9 @@ components:
                   codespace:
                     type: string
                     example: "ibc"
+            total_gas_used:
+              type: string
+              example: "100"
             begin_block_events:
               type: array
               nullable: true