Convert DivinerLiveSymbol to text, not bytes

Summary:
Ref T1191. The `bytes` types are BINARY(...), which is fixed-length and zero-pads. These hashes are not 64 characters long, so migrating them to `binary` ends up with a bunch of zero-padding.

Instead, migrate them to `text` so we drop the zero padding. It would be vaguely nice to either introduce a `varbytes` type (ick) or change the hash size to a standard size (nicer) eventually, but this isn't very important.

Test Plan: Will adjust `secure.phabricator.com`.

Reviewers: btrahan

Subscribers: epriestley

Maniphest Tasks: T1191

Differential Revision: https://secure.phabricator.com/D10613

src/applications/diviner/storage/DivinerLiveSymbol.php

@@ -33,13 +33,13 @@ final class DivinerLiveSymbol extends DivinerDAO
         'name' => 'text255',
         'atomIndex' => 'uint32',
         'identityHash' => 'bytes12',
-        'graphHash' => 'bytes64?',
+        'graphHash' => 'text64?',
         'title' => 'text?',
         'titleSlugHash' => 'bytes12?',
         'groupName' => 'text255?',
         'summary' => 'text?',
         'isDocumentable' => 'bool',
-        'nodeHash' => 'bytes64?',
+        'nodeHash' => 'text64?',
       ),
       self::CONFIG_KEY_SCHEMA => array(
         'key_phid' => null,