fix: accessibility - add button role to the expandable search additional filters

Author: guifry

src/frontend/view/view-search-panel.ts

@@ -37,7 +37,7 @@ const viewKeywordSearchPanel = () => `
             state.searchResults
               ? ''
               : `<details class="govuk-details" data-module="govuk-details">
-            <summary class="govuk-details__summary">
+            <summary class="govuk-details__summary" role="button">
               <span class="govuk-details__summary-text">
                 Search filters
               </span>
@@ -105,7 +105,7 @@ const viewLinkSearchPanel = () => `
           state.searchResults
             ? ''
             : `<details class="govuk-details" data-module="govuk-details">
-          <summary class="govuk-details__summary">
+          <summary class="govuk-details__summary" role="button">
             <span class="govuk-details__summary-text">
               Search filters
             </span>
@@ -139,7 +139,7 @@ const viewTaxonSearchPanel = () => `
             state.searchResults
               ? ''
               : `<details class="govuk-details" data-module="govuk-details">
-            <summary class="govuk-details__summary">
+            <summary class="govuk-details__summary" role="button">
               <span class="govuk-details__summary-text">
                 Search filters
               </span>
@@ -172,7 +172,7 @@ const viewLanguageSearchPanel = () => `
             state.searchResults
               ? ''
               : `<details class="govuk-details" data-module="govuk-details">
-            <summary class="govuk-details__summary">
+            <summary class="govuk-details__summary" role="button">
               <span class="govuk-details__summary-text">
                 Search filters
               </span>
@@ -205,7 +205,7 @@ const viewOrganisationSearchPanel = () => `
             state.searchResults
               ? ''
               : `<details class="govuk-details" data-module="govuk-details">
-            <summary class="govuk-details__summary">
+            <summary class="govuk-details__summary" role="button">
               <span class="govuk-details__summary-text">
                 Search filters
               </span>