[inline functions] Allow lambda parameters to be typed

[wrwg]

Currently the lambda expressions we are using for inline fun are derived from older support of lambdas in the specification language. Those lambdas (|v|e) do not allow for type annotations (|v:t|e). But we need the later since the Move compiler does not always infer the desired types, and annotations are needed. The current workaround is to use |v| { let v : T = v; e }.