added header and footer mapping in fallback

[ajayadav09]

Proposed changes

PRESS0-1871:
https://jira.newfold.com/browse/PRESS0-1871

• When the Primary Type and Secondary Type are not selected by the user, the header menu is rendered from the fallback theme and not fetched from the wonder-blocks. Since the fallback array did not have the header and footer the header-menu step in the DIY flow was breaking. Added the header and footer as a fallback.

• On the wp-setup/step/design/homepage-menu step, the chosen header menu was not reflecting in the homepage layout block grammar instead the default was shown everytime. Updated the logic for that.

Type of Change

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation Update (if none of the other choices apply)

Video

Checklist

• I have read the CONTRIBUTING doc
• I have viewed my change in a web-browser
• Linting and tests pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)

Further comments

[officiallygod]

Looks Good