Generate FromUriParam<Query> impls for some Option types

[Alexendoo]

I ran into this issue when trying to create next/prev page links while reusing existing optional parameters, something like

#[get("/route?<page>&<other>"]
fn route(page: usize, other: Option<String>) {
    let next = uri!(route, page + 1, other);
}

cc #998 (comment), it allows forms a and b for the added types

I tried creating a blanket impl for Option<T>, however that conflicts with the T -> Option<T> forwarding, so instead generate them for individual types using a macro

Option<&str>, Option<&RawStr> and Option<Cow<str>> are not included because they also generated conflicts with existing impls

[SergioBenitez]

I'm generally in favor, but I'm wondering if instead we should do this:

diff --git a/core/http/src/uri/from_uri_param.rs b/core/http/src/uri/from_uri_param.rs
index 416d3946..8e774107 100644
--- a/core/http/src/uri/from_uri_param.rs
+++ b/core/http/src/uri/from_uri_param.rs
@@ -338,7 +338,7 @@ impl<'a, 'b> FromUriParam<uri::Path, &'a &'b str> for PathBuf {
 }
 
 /// A no cost conversion allowing any `T` to be used in place of an `Option<T>`.
-impl<P: UriPart, A, T: FromUriParam<P, A>> FromUriParam<P, A> for Option<T> {
+impl<A, T: FromUriParam<uri::Path, A>> FromUriParam<uri::Path, A> for Option<T> {
     type Target = T::Target;
 
     #[inline(always)]
@@ -348,7 +348,7 @@ impl<P: UriPart, A, T: FromUriParam<P, A>> FromUriParam<P, A> for Option<T> {
 }
 
 /// A no cost conversion allowing `T` to be used in place of an `Result<T, E>`.
-impl<P: UriPart, A, E, T: FromUriParam<P, A>> FromUriParam<P, A> for Result<T, E> {
+impl<A, E, T: FromUriParam<uri::Path, A>> FromUriParam<uri::Path, A> for Result<T, E> {
     type Target = T::Target;
 
     #[inline(always)]
@@ -356,3 +356,39 @@ impl<P: UriPart, A, E, T: FromUriParam<P, A>> FromUriParam<P, A> for Result<T, E
         T::from_uri_param(param)
     }
 }
+
+impl<A, T: FromUriParam<uri::Query, A>> FromUriParam<uri::Query, Option<A>> for Option<T> {
+    type Target = Option<T::Target>;
+
+    #[inline(always)]
+    fn from_uri_param(param: Option<A>) -> Self::Target {
+        param.map(|a| T::from_uri_param(a))
+    }
+}
+
+impl<A, E, T: FromUriParam<uri::Query, A>> FromUriParam<uri::Query, Option<A>> for Result<T, E> {
+    type Target = Option<T::Target>;
+
+    #[inline(always)]
+    fn from_uri_param(param: Option<A>) -> Self::Target {
+        param.map(|a| T::from_uri_param(a))
+    }
+}
+
+impl<A, E, T: FromUriParam<uri::Query, A>> FromUriParam<uri::Query, Result<A, E>> for Result<T, E> {
+    type Target = Result<T::Target, E>;
+
+    #[inline(always)]
+    fn from_uri_param(param: Result<A, E>) -> Self::Target {
+        param.map(|a| T::from_uri_param(a))
+    }
+}
+
+impl<A, E, T: FromUriParam<uri::Query, A>> FromUriParam<uri::Query, Result<A, E>> for Option<T> {
+    type Target = Result<T::Target, E>;
+
+    #[inline(always)]
+    fn from_uri_param(param: Result<A, E>) -> Self::Target {
+        param.map(|a| T::from_uri_param(a))
+    }
+}