Add approving employee on refund

Just like for payment, it is good to know who approved a refund.

assigned to @ced

added accounting type::feature + 1 deleted label

added 1 deleted label and removed 1 deleted label

New review356071002 at https://codereview.tryton.org/356071002/#ps368191002

New changeset b291768f3a5e by Cédric Krier in branch 'default':
Add approving employee on refunds
https://hg.tryton.org/modules/account_payment_braintree/rev/b291768f3a5e

added 1 deleted label and removed 1 deleted label

closed

New changeset 53c0b88cade5 by Cédric Krier in branch 'default':
Add approving employee on refunds
https://hg.tryton.org/modules/account_payment_stripe/rev/53c0b88cade5

New changeset 320ba20a8889 by Cédric Krier in branch 'default':
Add approving employee on refunds
https://hg.tryton.org/tryton-env/rev/320ba20a8889