Table properties have no width when opening dialog after resizing table

[Jakub Ś]

1. Create new table with default width 500.
2. Switch to wysiwyg mode and resize it with FF native handles.
3. Right click on the table and select Table properties.

Result: Width has no value assigned.

This is happening because when using Firefox native resize handles, Firefox operates on attributes while CKEditor operates on styles what results in two widths (#9287).
Issue #9287 no longer occurs in CKE 4.1 RC but one does and can be reproduced from CKEditor 4.0 in Firefox browser.

[Jakub Ś]

NOTE: if you use //allowedContent : true (ACF switched off) then no matter how many times you switch to source and back and open table properties dialog, you won't see width value.

If you use default configuration (ACF not turned off) then:

1. You insert table
2. You resize it
3. You open table properties dialog and don't see width value
4. You switch to source and back
5. You open table properties dialog and now you see width value