V2Wizard: Replace h2 heading with h1 and sizing

This replaces h2 heading on the steps with h1 and adds a size modifier to keep the sizes approximately similar.

src/Components/CreateImageWizardV2/steps/Packages/index.tsx

@@ -7,7 +7,9 @@ import Packages from './Packages';
 const PackagesStep = () => {
   return (
     <Form>
-      <Title headingLevel="h2">Additional packages</Title>
+      <Title headingLevel="h1" size="xl">
+        Additional packages
+      </Title>
       <Text>
         Images built with Image Builder include all required packages.
       </Text>