Add overview of active sessions (#3929)

* Add overview of active sessions

* Better display of browser/platform name

* Improve how browser information is stored and displayed for sessions overview

* Fix test

config/locales/en.yml

@@ -320,6 +320,43 @@ en:
     missing_resource: Could not find the required redirect URL for your account
     proceed: Proceed to follow
     prompt: 'You are going to follow:'
+  sessions:
+    activity: Last activity
+    browser: Browser
+    browsers:
+      alipay: Alipay
+      blackberry: Blackberry
+      chrome: Chrome
+      edge: Microsoft Edge
+      firefox: Firefox
+      generic: Unknown browser
+      ie: Internet Explorer
+      micro_messenger: MicroMessenger
+      nokia: Nokia S40 Ovi Browser
+      opera: Opera
+      phantom_js: PhantomJS
+      qq: QQ Browser
+      safari: Safari
+      uc_browser: UCBrowser
+      weibo: Weibo
+    current_session: Current session
+    description: "%{browser} on %{platform}"
+    explanation: These are the web browsers currently logged in to your Mastodon account.
+    ip: IP
+    platforms:
+      adobe_air: Adobe Air
+      android: Android
+      blackberry: Blackberry
+      chrome_os: ChromeOS
+      firefox_os: Firefox OS
+      ios: iOS
+      linux: Linux
+      mac: Mac
+      other: unknown platform
+      windows: Windows
+      windows_mobile: Windows Mobile
+      windows_phone: Windows Phone
+    title: Sessions
   settings:
     authorized_apps: Authorized apps
     back: Back to Mastodon