api-ref - stack identity usage in find calls

The Heat API for find-stack accepts either the stack name or the stack
UUID when retrieving the canonical URL for a stack resource. The
current documentation is inaccurate because it is described as only
accepting stack names.

Change-Id: Ic2dba4314d5fc7e8bef460e92d94b92f87635d71

api-ref/source/v1/parameters.yaml

@@ -64,7 +64,13 @@ stack_id_url:
   description: |
     The UUID of the stack.
   in: path
-  required: false
+  required: true
+  type: string
+stack_identity:
+  description: |
+    The UUID or the name of a stack.
+  in: path
+  required: true
   type: string
 stack_name_url:
   description: |

api-ref/source/v1/stacks.inc

@@ -217,7 +217,7 @@ Response Example
 Find stack
 ==========
 
-.. rest_method::  GET /v1/{tenant_id}/stacks/{stack_name}
+.. rest_method::  GET /v1/{tenant_id}/stacks/{stack_identity}
 
 Finds the canonical URL for a stack.
 
@@ -248,7 +248,7 @@ Request Parameters
 .. rest_parameters:: parameters.yaml
 
    - tenant_id: tenant_id
-   - stack_name: stack_name_url
+   - stack_identity: stack_identity
 
 Response Parameters
 -------------------
@@ -469,7 +469,7 @@ Response Example
 Find stack for deletion
 =======================
 
-.. rest_method::  DELETE /v1/{tenant_id}/stacks/{stack_name}
+.. rest_method::  DELETE /v1/{tenant_id}/stacks/{stack_identity}
 
 Find the canonical URL for a stack for deletion. This request returns a status
 code of ``302`` pointing to the location where a DELETE request can be sent to
@@ -495,7 +495,7 @@ Request Parameters
 .. rest_parameters:: parameters.yaml
 
    - tenant_id: tenant_id
-   - stack_name: stack_name_url
+   - stack_identity: stack_identity
 
 Reponse Parameters
 ------------------