feat(go): adding helper methods for result and option (#1463)

Signed-off-by: Andrew Steurer <94206073+asteurer@users.noreply.github.com>

Author: asteurer

crates/go/src/wit_option.go

@@ -29,6 +29,14 @@ func (self Option[T]) SomeOr(value T) T {
 	}
 }
 
+func (self Option[T]) IsSome() bool {
+	return self.tag == OptionSome
+}
+
+func (self Option[T]) IsNone() bool {
+	return self.tag == OptionNone
+}
+
 func None[T any]() Option[T] {
 	return Option[T]{OptionNone, make([]T, 1)[0]}
 }

crates/go/src/wit_result.go

@@ -28,6 +28,14 @@ func (self Result[T, U]) Err() U {
 	return self.value.(U)
 }
 
+func (self Result[T, U]) IsErr() bool {
+	return self.tag == ResultErr
+}
+
+func (self Result[T, U]) IsOk() bool {
+	return self.tag == ResultOk
+}
+
 func Ok[T any, U any](value T) Result[T, U] {
 	return Result[T, U]{ResultOk, value}
 }