Add an encoded character to the GetMenu request tests

[bpholt]

The Smithy spec says that in HTTP labels used in HTTP request URIs,

Characters not defined as unreserved by RFC 3986 section 2.3 MUST be percent-encoded. That is, all characters except for alphanumerics and -._~.

This PR adds an example of such a character used in the value bound to the GetMenu request's {restaurant} label, along with the expected encoding.

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[bpholt]

I published this locally and used it with disneystreaming/smithy4s#1668. I think that will need to be merged before this can be pulled into smithy4s because otherwise this test case should fail.

[Baccata]

👍 thank you Brian. I'll try to give the smithy4s PR tomorrow a review today (but if I don't I promise I'll do it tomorrow)