Only serve attachments when linked to issue/release and if accessible by user (#9340)

* test: add current attachement responses

* refactor: check if attachement is linked and accessible by user

* chore: clean TODO

* fix: typo attachement -> attachment

* revert un-needed go.sum change

* refactor: move models logic to models

* fix TestCreateIssueAttachment which was wrongly successful

* fix unit tests with unittype added

* fix unit tests with changes

* use a valid uuid format for pgsql int. test

* test: add unit test TestLinkedRepository

* refactor: allow uploader to access unlinked attachement

* add missing blank line

* refactor: move to a separate function repo.GetAttachment

* typo

* test: remove err test return

* refactor: use repo perm for access checking generally + 404 for all reject

models/fixtures/attachment.yml

@@ -10,7 +10,7 @@
 -
   id: 2
   uuid: a0eebc99-9c0b-4ef8-bb6d-6bb9bd380a12
-  issue_id: 1
+  issue_id: 4
   comment_id: 0
   name: attach2
   download_count: 1
@@ -81,6 +81,15 @@
 -
   id: 10
   uuid: a0eebc99-9c0b-4ef8-bb6d-6bb9bd380a20
+  uploader_id: 8
   name: attach1
   download_count: 0
-  created_unix: 946684800 
+  created_unix: 946684800
+
+-
+  id: 11
+  uuid: a0eebc99-9c0b-4ef8-bb6d-6bb9bd380a21
+  release_id: 2
+  name: attach1
+  download_count: 0
+  created_unix: 946684800

models/fixtures/release.yml

@@ -11,4 +11,19 @@
   is_draft: false
   is_prerelease: false
   is_tag: false
-  created_unix: 946684800
+  created_unix: 946684800
+
+-
+  id: 2
+  repo_id: 40
+  publisher_id: 2
+  tag_name: "v1.1"
+  lower_tag_name: "v1.1"
+  target: "master"
+  title: "testing-release"
+  sha1: "65f1bf27bc3bf70f64657658635e66094edbcb4d"
+  num_commits: 10
+  is_draft: false
+  is_prerelease: false
+  is_tag: false
+  created_unix: 946684800

models/fixtures/repo_unit.yml

@@ -472,4 +472,10 @@
   repo_id: 48
   type: 7
   config: "{\"ExternalTrackerURL\":\"https://tracker.com\",\"ExternalTrackerFormat\":\"https://tracker.com/{user}/{repo}/issues/{index}\",\"ExternalTrackerStyle\":\"alphanumeric\"}"
+  created_unix: 946684810
+-
+  id: 69
+  repo_id: 2
+  type: 2
+  config: "{}"
   created_unix: 946684810