Proposal export doesn't include all selected proposals

[simonfernandes]

When you select a list of proposals and "Export proposals in Excel", it will only include the first 20 proposals in the exported spreadsheet. All proposals need to show in the spreadsheet for it to be useful and to avoid repetition.

E.g. when you click the button to select all proposals, it will only include however many are in the list view. In the following screenshot that would be 20 proposals, despite clicking "select all 38 proposals".

Reported by Emma Gozzard in a backlog pruning meeting.