Added header suggestions

lib/widgets/headerfield.dart

@@ -0,0 +1,90 @@
+import 'package:apidash/utils/header_utils.dart';
+import 'package:flutter/material.dart';
+import 'package:apidash/consts.dart';
+import 'package:flutter_typeahead/flutter_typeahead.dart';
+
+class HeaderField extends StatefulWidget {
+  const HeaderField({
+    super.key,
+    required this.keyId,
+    required this.controller,
+    this.hintText,
+    this.onChanged,
+    this.colorScheme,
+  });
+  final TextEditingController controller;
+  final String keyId;
+  final String? hintText;
+  final void Function(String)? onChanged;
+  final ColorScheme? colorScheme;
+
+  @override
+  State<HeaderField> createState() => _HeaderFieldState();
+}
+
+class _HeaderFieldState extends State<HeaderField> {
+  @override
+  Widget build(BuildContext context) {
+    var colorScheme = widget.colorScheme ?? Theme.of(context).colorScheme;
+    return TypeAheadFormField(
+      minCharsForSuggestions: 1,
+      hideOnEmpty: true,
+      key: Key(widget.keyId),
+      onSuggestionSelected: widget.onChanged!,
+      itemBuilder: (context, String suggestion) {
+        return ListTile(
+          dense: true,
+          title: Text(suggestion),
+        );
+      },
+      suggestionsCallback: getHeaderSuggestions,
+      suggestionsBoxDecoration: suggestionBoxDecorations(context),
+      textFieldConfiguration: TextFieldConfiguration(
+        onChanged: widget.onChanged!,
+        controller: widget.controller,
+        style: kCodeStyle.copyWith(
+          color: colorScheme.onSurface,
+        ),
+        decoration: InputDecoration(
+          hintStyle: kCodeStyle.copyWith(
+            color: colorScheme.outline.withOpacity(
+              kHintOpacity,
+            ),
+          ),
+          hintText: widget.hintText,
+          focusedBorder: UnderlineInputBorder(
+            borderSide: BorderSide(
+              color: colorScheme.primary.withOpacity(
+                kHintOpacity,
+              ),
+            ),
+          ),
+          enabledBorder: UnderlineInputBorder(
+            borderSide: BorderSide(
+              color: colorScheme.surfaceVariant,
+            ),
+          ),
+        ),
+      ),
+    );
+  }
+
+  SuggestionsBoxDecoration suggestionBoxDecorations(BuildContext context) {
+    return SuggestionsBoxDecoration(
+      elevation: 4,
+      constraints: const BoxConstraints(maxHeight: 400),
+      shape: RoundedRectangleBorder(
+        side: BorderSide(
+          color: Theme.of(context).dividerColor,
+          width: 1.2,
+        ),
+        borderRadius: const BorderRadius.vertical(bottom: Radius.circular(8)),
+      ),
+      clipBehavior: Clip.hardEdge,
+    );
+  }
+
+  Future<List<String>> headerSuggestionCallback(String pattern) async {
+    return getHeaderSuggestions(pattern);
+  }
+}