Move title bar functionality to rail (#1816)

Summary:
Pull Request resolved: https://github.com/facebook/flipper/pull/1816

Now that Sandy is the default in OSS builds as well, we can remove the temporarily title bar and switch to small topbar windows in Electron.

This diff removes any remaining elements in the titlebar

- version number went into the title bar
- the update check warning is shown on top of the bottom section of the left rail (orange triangle)
- the development only perf graphs are moved to the left bar as well and are now aligned vertically.

Reviewed By: jknoxville

Differential Revision: D25805957

fbshipit-source-id: fba4b60c246b8f5d99a93087af31af9ac55defe8

desktop/static/main.ts

@@ -268,8 +268,6 @@ function createWindow() {
     minWidth: 800,
     minHeight: 600,
     center: true,
-    titleBarStyle: 'hiddenInset',
-    vibrancy: 'sidebar',
     webPreferences: {
       enableRemoteModule: true,
       backgroundThrottling: false,