Repository avatars (#6986)

* Repository avatars

- first variant of code from old work for gogs
- add migration 87
- add new option in app.ini
- add en-US locale string
- add new class in repository.less

* Add changed index.css, remove unused template name

* Update en-us doc about configuration options

* Add comments to new functions, add new option to docker app.ini

* Add comment for lint

* Remove variable, not needed

* Fix formatting

* Update swagger api template

* Check if avatar exists

* Fix avatar link/path checks

* Typo

* TEXT column can't have a default value

* Fixes:

- remove old avatar file on upload
- use ID in name of avatar file - users may upload same files
- add simple tests

* Fix fmt check

* Generate PNG instead of "static" GIF

* More informative comment

* Fix error message

* Update avatar upload checks:

- add file size check
- add new option
- update config docs
- add new string to en-us locale

* Fixes:

- use FileHEader field for check file size
- add new test - upload big image

* Fix formatting

* Update comments

* Update log message

* Removed wrong style - not needed

* Use Sync2 to migrate

* Update repos list view

- bigger avatar
- fix html blocks alignment

* A little adjust avatar size

* Use small icons for explore/repo list

* Use new cool avatar preparation func by @lafriks

* Missing changes for new function

* Remove unused import, move imports

* Missed new option definition in app.ini

Add file size check in user/profile avatar upload

* Use smaller field length for Avatar

* Use session to update repo DB data, update DeleteAvatar - use session too

* Fix err variable definition

* As suggested @lafriks - return as soon as possible, code readability

public/css/index.css

@@ -956,6 +956,7 @@ tbody.commit-list{vertical-align:baseline}
 .ui.repository.list .item .ui.header .metas span:not(:last-child){margin-right:5px}
 .ui.repository.list .item .time{font-size:12px;color:grey}
 .ui.repository.list .item .ui.tags{margin-bottom:1em}
+.ui.repository.list .item .ui.avatar.image{width:24px;height:24px}
 .ui.repository.branches .time{font-size:12px;color:grey}
 .ui.user.list .item{padding-bottom:25px}
 .ui.user.list .item:not(:first-child){border-top:1px solid #eee;padding-top:25px}

public/less/_explore.less

@@ -53,6 +53,11 @@
         .ui.tags {
             margin-bottom: 1em;
         }
+
+        .ui.avatar.image {
+            width: 24px;
+            height: 24px;
+        }
     }
 }