In dashboard configuration, when you click on file of 'Data' section in
debug mode to edit, icons were duplicated.
This commit fixes the issue by getting rid of the same icons in
overridden template `web.ListBinaryField` from `binary_field.xml`
in order to remove icon duplicacy.
Additionaly, this commit removes unnecessary `<i>` tags and alters the
classes of `<button>` tags instead, to maintain the visual appearance
of icons (now they look the same as everywhere else).
Task ID : 3453198
closesodoo/odoo#134005
X-original-commit: 850e16cc415486507d1984ea08a04140ffba7c61
Signed-off-by: Rémi Rahir (rar) <rar@odoo.com>