feat(ffi): add hyper_request_set_uri_parts

Add a second FFI interface for setting the URI of a request with three
separate schema, authority, and path/query strings, rather than one URI
string.

capi/include/hyper.h

@@ -430,6 +430,23 @@ enum hyper_code hyper_request_set_uri(struct hyper_request *req,
                                       const uint8_t *uri,
                                       size_t uri_len);
 
+/*
+ Set the URI of the request with separate scheme, authority, and
+ path/query strings.
+
+ Each of `scheme`, `authority`, and `path_and_query` should either be
+ null, to skip providing a component, or point to a UTF-8 encoded
+ string. If any string pointer argument is non-null, its corresponding
+ `len` parameter must be set to the string's length.
+ */
+enum hyper_code hyper_request_set_uri_parts(struct hyper_request *req,
+                                            const uint8_t *scheme,
+                                            size_t scheme_len,
+                                            const uint8_t *authority,
+                                            size_t authority_len,
+                                            const uint8_t *path_and_query,
+                                            size_t path_and_query_len);
+
 /*
  Set the preferred HTTP version of the request.