[REF] Fix Screen reader accessibility of attachment fields

[seamuslee001]

Overview

This ensures that each file field correctly has a label assigned to it for screen readers and the description field is also properly labelled

Before

Labels incorrectly referencing attachfile_1 and no label on description fields

After

labels fixed

@monishdeb @eileenmcnaughton @colemanw @JoeMurray

[civibot]

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[eileenmcnaughton]

@vingle

[vingle]

Test this please

[vingle]

This reads like a good improvement, but haven't tested.

[vingle]

test this please

[vingle]

Works for me: improves accessibility and functionality isn't impacted. Good to go.