[InfraUI] [LogsUI] Accessibility fixes (#41883)

* Fixes #40411 - Add aria-label to search input

* Fixes #40425 - Align gear icon aria-labels

* Fixes #40419 - Make use of EuiDescribedFormGroup in the source configuration panel

* Add data-test-subj attribute back for functional test

* Revert "Fixes #40419 - Make use of EuiDescribedFormGroup in the source configuration panel"

This reverts commit 5075777e53.

x-pack/legacy/plugins/infra/public/components/autocomplete_field/autocomplete_field.tsx

@@ -28,6 +28,7 @@ interface AutocompleteFieldProps {
   suggestions: AutocompleteSuggestion[];
   value: string;
   autoFocus?: boolean;
+  'aria-label'?: string;
 }
 
 interface AutocompleteFieldState {
@@ -49,7 +50,14 @@ export class AutocompleteField extends React.Component<
   private inputElement: HTMLInputElement | null = null;
 
   public render() {
-    const { suggestions, isLoadingSuggestions, isValid, placeholder, value } = this.props;
+    const {
+      suggestions,
+      isLoadingSuggestions,
+      isValid,
+      placeholder,
+      value,
+      'aria-label': ariaLabel,
+    } = this.props;
     const { areSuggestionsVisible, selectedIndex } = this.state;
 
     return (
@@ -67,6 +75,7 @@ export class AutocompleteField extends React.Component<
             onSearch={this.submit}
             placeholder={placeholder}
             value={value}
+            aria-label={ariaLabel}
           />
           {areSuggestionsVisible && !isLoadingSuggestions && suggestions.length > 0 ? (
             <SuggestionsPanel>

x-pack/legacy/plugins/infra/public/components/logging/log_text_stream/column_headers.tsx

@@ -31,7 +31,7 @@ export const LogColumnHeaders = injectI18n<{
 }>(({ columnConfigurations, columnWidths, intl, showColumnConfiguration }) => {
   const showColumnConfigurationLabel = intl.formatMessage({
     id: 'xpack.infra.logColumnHeaders.configureColumnsLabel',
-    defaultMessage: 'Configure columns',
+    defaultMessage: 'Configure source',
   });
 
   return (

x-pack/legacy/plugins/infra/public/pages/logs/page_toolbar.tsx

@@ -80,6 +80,10 @@ export const LogsToolbar = injectI18n(({ intl }) => {
                     })}
                     suggestions={suggestions}
                     value={filterQueryDraft ? filterQueryDraft.expression : ''}
+                    aria-label={intl.formatMessage({
+                      id: 'xpack.infra.logsPage.toolbar.kqlSearchFieldAriaLabel',
+                      defaultMessage: 'Search for log entries',
+                    })}
                   />
                 )}
               </WithLogFilter>