Trim underscore prefix while generating event params

Underscore prefixes should be trimmed while
capitalizing and uncapitalizing the first
letter of the event params. This change
is required because abigen does the same
while generating the underlying contract
binding so names must be aligned to
avoid compilation errors.

tools/generators/ethereum/contract_parsing.go

@@ -278,13 +278,19 @@ func uppercaseFirst(str string) string {
 	if len(str) == 0 {
 		return str
 	}
+
+	str = strings.TrimPrefix(str, "_")
+
 	return strings.ToUpper(str[0:1]) + str[1:]
 }
 
 func lowercaseFirst(str string) string {
 	if len(str) == 0 {
 		return str
 	}
+
+	str = strings.TrimPrefix(str, "_")
+
 	return strings.ToLower(str[0:1]) + str[1:]
 }