Delete menu - similar strings and HTML

[pavelevap]

• Menu in Customizer

String: "Delete menu"
HTML: Button
https://core.trac.wordpress.org/browser/tags/4.3/src/wp-includes/class-wp-customize-control.php#L1585

• Menu page

String: "Delete Menu" (both capital letters)
HTML: Link
https://core.trac.wordpress.org/browser/tags/4.3/src/wp-admin/nav-menus.php#L813

1) I only wanted to merge same strings, but I found other issues.

2) Also HTML should be the same (button)?

3) {{ data.menu_name }} as screen reader text does not print anything.

4) For localization it should be string like Delete menu <span class="screen-reader-text">%s</span>?

[ocean90]

In 35695:

Customizer: Merge two similar strings.

Remove also {{ data.menu_name }} since it doesn't print anything.

Fixes #33630.