Update the upload page copy to be format specific

This commit changes how the supported file format is configured on a
bucket. The configuration name was changed to because the upload format
is no longer just used for parsing but also controlling which template
is used.
Merge pull request #123 from alphagov/update-upload-page-copy

Update the upload page copy to be format specific
Add lpa and hmrc to bucket access
Merge pull request #125 from alphagov/fix_bucket_access

Add lpa and hmrc to bucket access