[PRM-45] WCAG 3.3.2: Missing label on file upload form input control (#602)

* Gives Select Files button an aria label described by fieldset legend

* Edits tests to use new label

Author: jack-nhs

app/src/components/blocks/_lloydGeorge/lloydGeorgeFileInputStage/LloydGeorgeFileInputStage.test.tsx

@@ -83,7 +83,9 @@ describe('<LloydGeorgeFileInputStage />', () => {
                 screen.getByText('NHS number: ' + formatNhsNumber(mockPatient.nhsNumber)),
             ).toBeInTheDocument();
 
-            expect(screen.getByRole('button', { name: 'Select files' })).toBeInTheDocument();
+            expect(
+                screen.getByRole('button', { name: 'Select the files you wish to upload' }),
+            ).toBeInTheDocument();
 
             expect(screen.getByRole('button', { name: 'Upload' })).toBeInTheDocument();
             expect(screen.getByRole('button', { name: 'Upload' })).toBeEnabled();

app/src/components/blocks/_lloydGeorge/lloydGeorgeFileInputStage/LloydGeorgeFileInputStage.tsx

@@ -161,7 +161,9 @@ function LloydGeorgeFileInputStage({ documents, setDocuments, submitDocuments }:
                 </p>
                 <p>You will not be able to view a partially uploaded record.</p>
             </div>
-            <Fieldset.Legend size="m">Select the files you wish to upload</Fieldset.Legend>
+            <Fieldset.Legend id="upload-fieldset-legend" size="m">
+                Select the files you wish to upload
+            </Fieldset.Legend>
             <Fieldset>
                 <div
                     role="button"
@@ -202,6 +204,7 @@ function LloydGeorgeFileInputStage({ documents, setDocuments, submitDocuments }:
                             onClick={() => {
                                 fileInputRef.current?.click();
                             }}
+                            aria-labelledby="upload-fieldset-legend"
                         >
                             Select files
                         </Button>