Code review comment for lp:~laetitia-gangloff/account-invoicing/account_invoice_merge

Got some remarks on the view:
'account_invoice_merge/wizard/invoice_merge_view.xml'

You use form version 7 but still use a label with a big ugly string which contains '
' characters to break lines.
I would think that using clean and simple html would be a better fit here ? Perhaps a few clean <p> tags to bundle the text.

A question about the merge key, would it not be better to use the commercial_entity instead of the regular partner_id ?
This could obviously lead to somewhat unexpected behaviour which will merge invoices that were meant for different departments within a company maybe but this itself could also be considered a desireable feature.
Perhaps the merge wizard should ask the user if it has to merge invoices for the same entity or only per "address"?