Ensure menu items with sym/str names can be sorted

[johansenja]

Hello - I recently updated a few gems locally in one of my apps (including Trestle 0.9.5 to 0.9.7), and for some reason this broke Trestle pages in the app, with a fairly cryptic error:

After a lot of digging, I realised it was because some of our menu items had their names defined as symbols (eg :blog_posts), and some as strings ("Longer name written as string"), so because Menu::Item#<=> looks at the name, and because :symbol <=> "string" returns nil, this was breaking the sorting (but coming from quite a deep place).

It's quite a simple fix, but happy to share a bit more context if it's helpful!

[CLAassistant]

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[spohlenz]

Thank you for the fix!