[v3] Fix binding generator output and import paths (#3334)

* Fix relative import path computation

* Fix models output path

* Add option to generate bindings using bundled runtime

* Update binding example

* Fix testdata

* Update changelog

---------

Co-authored-by: Lea Anthony <lea.anthony@gmail.com>

v3/examples/binding/data/person.go

@@ -0,0 +1,7 @@
+package data
+
+// Person holds someone's most important attributes
+type Person struct {
+	// Name is the person's name
+	Name string `json:"name"`
+}