[13] Optional Column buttons very difficult to see with right-justified columns

[rallytime]

Impacted versions: 13

Steps to reproduce:

1. Create a tree view where at least one column is using optional=<show/hide>
2. Create a column on the far right that is right-justified (such as a "float" type)
3. Try to see where the 3 dots are to select optional columns.

Current behavior:

The optional dot image is squashed together with the title text from the right-justified column header:

Expected behavior:

You can see both the column header title and the optional "dots" clearly, just like in other column views that are left-justified:

Additional Info:

To reproduce this easily, you can use the view_stock_move_raw_tree XML record in addons/mrp/views/stock_move_views.xml and change any of the visible fields to use "optional" - this is what I have done in my screen shots above.