Add linter checks to GHA & Fix code to pass lints

Add linter checks to GHA & Fix code to pass lints.
The linters added are:
- whitespace: Tool for detection of leading and trailing whitespace
- gosec: Inspects source code for security problems
- gci: Gci control golang package import order and make it always deterministic
- misspell: Finds commonly misspelled English words in comments
- gomnd: An analyzer to detect magic numbers

The file utils/utils.go is excluded from the checks of gomnd, as uses magic numbers through the code

db/historydb/historydb.go

@@ -7,7 +7,9 @@ import (
 	"github.com/hermeznetwork/hermez-node/common"
 	"github.com/hermeznetwork/hermez-node/db"
 	"github.com/jmoiron/sqlx"
-	_ "github.com/lib/pq" // driver for postgres DB
+
+	//nolint:errcheck // driver for postgres DB
+	_ "github.com/lib/pq"
 	migrate "github.com/rubenv/sql-migrate"
 	"github.com/russross/meddler"
 )

db/historydb/historydb_test.go

@@ -49,8 +49,8 @@ func TestBlocks(t *testing.T) {
 	// Generate fake blocks
 	blocks := genBlocks(fromBlock, toBlock)
 	// Insert blocks into DB
-	for _, block := range blocks {
-		err := historyDB.AddBlock(&block)
+	for i := 0; i < len(blocks); i++ {
+		err := historyDB.AddBlock(&blocks[i])
 		assert.NoError(t, err)
 	}
 	// Get all blocks from DB