Add API for Issue set Subscription (#8729)

* add issue subscriber API

* subscribers return []user.APIFormat

* add comments

* more meaningfull description

* without "reqToken()" api works ...
 * should be still secure beause ctx.user has to be there or nothing will hapen

* FIX: getIssueWatchers() get only aktive suscriber

* add return avter error on right position

* Revert "FIX: getIssueWatchers() get only aktive suscriber"

This reverts commit 5eca9291858a821981992b0aaa38cef610d84bca.

* Update routers/api/v1/repo/issue.go

Co-Authored-By: guillep2k <18600385+guillep2k@users.noreply.github.com>

* test go linter again

* update swagger

* GetIssueWatchers -> GetIssueSubscribers

part one

Co-Authored-By: guillep2k <18600385+guillep2k@users.noreply.github.com>

* GetIssueWatchers -> GetIssueSubscribers
part two

* Revert "test go linter again"

This reverts commit bab12356227e44334de113b76f12099de0b8aaa6.

* change description for unsubscribe too

* golangci-lint timeout avter 5min

* move issueSubscription to seperate file

* dont create black entitys

* use IsWatching until refactoring

* Update License Info

* better swagger description

* Update .golangci.yml

because functions moved from issue.go to issue_subscription.go

* add IssueWatchList type

* batch tasks

* use e Engien

* add error handling

* error should be the last type when returning multiple items

* short version

* reurn empy UserList instead of nil

1 files changed, 159 insertions, 0 deletions

diff --git a/templates/swagger/v1_json.tmpl b/templates/swagger/v1_json.tmpl
index da7ebda852..41e5353ea7 100644
--- a/templates/swagger/v1_json.tmpl
+++ b/templates/swagger/v1_json.tmpl
@@ -3781,6 +3781,165 @@
         }
       }
     },
+    "/repos/{owner}/{repo}/issues/{index}/subscriptions": {
+      "get": {
+        "consumes": [
+          "application/json"
+        ],
+        "produces": [
+          "application/json"
+        ],
+        "tags": [
+          "issue"
+        ],
+        "summary": "Get users who subscribed on an issue.",
+        "operationId": "issueSubscriptions",
+        "parameters": [
+          {
+            "type": "string",
+            "description": "owner of the repo",
+            "name": "owner",
+            "in": "path",
+            "required": true
+          },
+          {
+            "type": "string",
+            "description": "name of the repo",
+            "name": "repo",
+            "in": "path",
+            "required": true
+          },
+          {
+            "type": "integer",
+            "format": "int64",
+            "description": "index of the issue",
+            "name": "index",
+            "in": "path",
+            "required": true
+          }
+        ],
+        "responses": {
+          "201": {
+            "$ref": "#/responses/empty"
+          },
+          "404": {
+            "description": "Issue not found"
+          }
+        }
+      }
+    },
+    "/repos/{owner}/{repo}/issues/{index}/subscriptions/{user}": {
+      "put": {
+        "consumes": [
+          "application/json"
+        ],
+        "produces": [
+          "application/json"
+        ],
+        "tags": [
+          "issue"
+        ],
+        "summary": "Subscribe user to issue",
+        "operationId": "issueAddSubscription",
+        "parameters": [
+          {
+            "type": "string",
+            "description": "owner of the repo",
+            "name": "owner",
+            "in": "path",
+            "required": true
+          },
+          {
+            "type": "string",
+            "description": "name of the repo",
+            "name": "repo",
+            "in": "path",
+            "required": true
+          },
+          {
+            "type": "integer",
+            "format": "int64",
+            "description": "index of the issue",
+            "name": "index",
+            "in": "path",
+            "required": true
+          },
+          {
+            "type": "string",
+            "description": "user to subscribe",
+            "name": "user",
+            "in": "path",
+            "required": true
+          }
+        ],
+        "responses": {
+          "201": {
+            "$ref": "#/responses/empty"
+          },
+          "304": {
+            "description": "User can only subscribe itself if he is no admin"
+          },
+          "404": {
+            "description": "Issue not found"
+          }
+        }
+      },
+      "delete": {
+        "consumes": [
+          "application/json"
+        ],
+        "produces": [
+          "application/json"
+        ],
+        "tags": [
+          "issue"
+        ],
+        "summary": "Unsubscribe user from issue",
+        "operationId": "issueDeleteSubscription",
+        "parameters": [
+          {
+            "type": "string",
+            "description": "owner of the repo",
+            "name": "owner",
+            "in": "path",
+            "required": true
+          },
+          {
+            "type": "string",
+            "description": "name of the repo",
+            "name": "repo",
+            "in": "path",
+            "required": true
+          },
+          {
+            "type": "integer",
+            "format": "int64",
+            "description": "index of the issue",
+            "name": "index",
+            "in": "path",
+            "required": true
+          },
+          {
+            "type": "string",
+            "description": "user witch unsubscribe",
+            "name": "user",
+            "in": "path",
+            "required": true
+          }
+        ],
+        "responses": {
+          "201": {
+            "$ref": "#/responses/empty"
+          },
+          "304": {
+            "description": "User can only subscribe itself if he is no admin"
+          },
+          "404": {
+            "description": "Issue not found"
+          }
+        }
+      }
+    },
     "/repos/{owner}/{repo}/keys": {
       "get": {
         "produces": [