[Redesign] Clean up <select>

Summary: Ref T8099, Ref T8449. Adds a min width to selects (can't think of anything this breaks in ui) and adds space around space select.

Test Plan: Review a number of selects in different UIs, forms, dialogs.

Reviewers: btrahan, epriestley

Reviewed By: epriestley

Subscribers: epriestley, Korvin

Maniphest Tasks: T8099, T8449

Differential Revision: https://secure.phabricator.com/D13523

src/view/form/control/AphrontFormPolicyControl.php

@@ -351,6 +351,7 @@ final class AphrontFormPolicyControl extends AphrontFormControl {
         $space_phid),
       array(
         'name' => 'spacePHID',
+        'class' => 'aphront-space-select-control-knob',
       ));
 
     return $select;