Allow PSD uploads over 6MB

You can't currently upload PSD files over 6MB. This is because its
mimetype is `image/vnd.adobe.photoshop`. We think this is an image, and
non-GIF images have a limit of 6MB.

To fix this, we could do one of two things:

1. Add a special case for PSD files
2. Increase the size limit for unsupported image types such as this

I went with the second option.

Tested this by:

- adding automated tests
- uploading a ~9 MB PSD file
- uploading a ~1 MB PNG
- uploading a ~27 MB PNG (which worked because it's converted to a smaller JPEG)
- uploading a ~50 MB text file
- trying to upload a ~500 MB text file (which failed, as expected)

Addresses [DESKTOP-1168][].

[DESKTOP-1168]: https://signalmessenger.atlassian.net/browse/DESKTOP-1168

ts/views/conversation_view.ts

@@ -1695,29 +1695,9 @@ Whisper.ConversationView = Whisper.View.extend({
   },
 
   isSizeOkay(attachment: any) {
-    let limitKb = 1000000;
-    const type =
-      attachment.contentType === 'image/gif'
-        ? 'gif'
-        : attachment.contentType.split('/')[0];
-
-    switch (type) {
-      case 'image':
-        limitKb = 6000;
-        break;
-      case 'gif':
-        limitKb = 25000;
-        break;
-      case 'audio':
-        limitKb = 100000;
-        break;
-      case 'video':
-        limitKb = 100000;
-        break;
-      default:
-        limitKb = 100000;
-        break;
-    }
+    const limitKb = window.Signal.Types.Attachment.getUploadSizeLimitKb(
+      attachment.contentType
+    );
     // this needs to be cast properly
     // eslint-disable-next-line @typescript-eslint/ban-ts-comment
     // @ts-ignore