The dialogue to pick a file in file picker is not nicely styled

See screenshots for the following:

• The checkboxes are not well displayed
• The padding on the right of the text inputs is too small, they seem to close to the edge
• The info at the bottom do not have separator
• When there is a separator at the bottom, it is glued to both sides
• From an accessibility point of view, I'm pretty sure the file info are not properly ready as SPAN is not considered as a word separator
• Margins below and above the fields seems unnecessarily high

All themes are affected, so clean and base should be tested. To select base pass ?theme=base to the URL.