[api] Extend binary tracking information for media

- Show the project a binary is taken from inside of a medium
- Show medium package container

docs/api/api/binary_released.rng

@@ -49,6 +49,14 @@
         </element>
         <optional>
           <element name="publish">
+            <optional>
+              <!-- exists only if not identical. This is the case if it is 
+                   part of a medium, but the binary is taken from another
+                   project -->
+              <attribute name="project">
+                <data type="string" />
+              </attribute>
+            </optional>
             <attribute name="package">
               <data type="string" />
             </attribute>
@@ -57,6 +65,17 @@
             </attribute>
           </element>
         </optional>
+        <optional>
+          <!-- exists only if the binary is on a tracked medium -->
+          <element name="medium">
+            <attribute name="project">
+              <data type="string" />
+            </attribute>
+            <attribute name="package">
+              <data type="string" />
+            </attribute>
+          </element>
+        </optional>
         <optional>
           <element name="build">
             <attribute name="time">

src/api/app/models/binary_release.rb

@@ -145,7 +145,10 @@ def render_xml
       binary.operation(operation)
 
       node = {}
-      node[:package] = release_package.name if release_package
+      if release_package
+        node[:project] = release_package.project.name if release_package.project != repository.project
+        node[:package] = release_package.name
+      end
       node[:time] = binary_releasetime if binary_releasetime
       node[:flavor] = flavor if flavor
       binary.publish(node) unless node.empty?
@@ -168,6 +171,11 @@ def render_xml
         binary.updatefor(up.extend_id_hash(project: up.package.project.name, product: up.name))
       end
 
+      if medium && (medium_package = on_medium.try(:release_package))
+        binary.medium(project: medium_package.project.name,
+                      package: medium_package.name)
+      end
+
       if product_medium
         binary.product(product_medium.product.extend_id_hash(name: product_medium.product.name))
       end