Update Navigation menus for Gutenberg 12.3.0 / WordPress 5.9

[bobbingwide]

Another thing that happens with the site editor is that my menus get wiped out.
For example the original footer-menu template part:

<!-- wp:navigation {"orientation":"horizontal","itemsJustification":"center"} -->
<!-- wp:navigation-link {"label":"Home","url":"https://s.b/wp56/"} /-->
<!-- wp:navigation-link {"label":"Blog","url":"https://s.b/wp56/blog/"} /-->
<!-- wp:navigation-link {"label":"Sitemap","url":"https://s.b/wp56/sitemap/"} /-->
<!-- wp:navigation-link {"label":"Sites","url":"https://s.b/wp56/sites/"} /-->
<!-- /wp:navigation -->

became

<!-- wp:navigation {"overlayMenu":"never",
"layout":{"type":"flex","setCascadingProperties":"true","justifyContent":"center","orientation":"horizontal"}} /-->

Originally posted by @bobbingwide in #72 (comment)

[bobbingwide]

In s.b/wp55/fizzie a Navigation menu was created but it was empty.

[bobbingwide]

delivered in v1.0.0