Refactor Issues Subscription (#8738)

* FIX: getIssueWatchers() get only aktive suscriber

* save query to work later with it or not ...

* fix test + add new case

* corect tests + GetIssueWatch

* API issue_subscripton: Put/Delete require tocken

* remove redundant code

* swagger specify return value

* remove unused binding

* remove note
because I'll implement this in a different way and in another PR

* ID should be unique!

* use xorm session

* Revert "use xorm session"

This reverts commit c1de540147.

* better test code
* more acurate comments
* use assert.False/True instead of Equal

* use more assert methodes

templates/swagger/v1_json.tmpl

@@ -3832,8 +3832,8 @@
           }
         ],
         "responses": {
-          "201": {
-            "$ref": "#/responses/empty"
+          "200": {
+            "$ref": "#/responses/UserList"
           },
           "404": {
             "description": "Issue not found"