Sprint names surrounded by back ticks when appropriate

[stephen-swensen]

e.g. instead of

``

let hello world = 23;; val ( hello world ) : int = 23

unquote <@ hello world @>;; val it : UnquotedExpression = hello world 23 ``

do

``

let hello world = 23;; val ( hello world ) : int = 23

unquote <@ hello world @>;; val it : UnquotedExpression = hello world 23 ``

it appears we did some work related to this a long time ago, to support back-ticked names at all, but without outputting the actual back ticks: https://github.com/SwensenSoftware/unquote/issues/87

[stephen-swensen]

Actually, this is in fact a duplicate of #87 we just forgot to implement the appropriate decompilation in recent ValueWithName