poll: Display ink splash UI feedback on poll delay

Added Material Widget and InkWell widget,
shifted the decoration of container to material
to make sure Ink splash occurs on the top of Material.

Fixes: #1808

Author: MritunjayTiwari14

lib/widgets/poll.dart

@@ -87,32 +87,32 @@ class _PollWidgetState extends State<PollWidget> {
         crossAxisAlignment: CrossAxisAlignment.baseline,
         textBaseline: localizedTextBaseline(context),
         children: [
-          GestureDetector(
-            // TODO: Implement feedback when the user taps the button
-            onTap: () => _toggleVote(option),
-            behavior: HitTestBehavior.translucent,
-            child: ConstrainedBox(
-              constraints: const BoxConstraints(minWidth: 44, minHeight: 44),
-              child: Padding(
-                // For accessibility, the touch target is padded to be larger
-                // than the vote count box.  Still, we avoid padding at the
-                // start because we want to align all the poll options to the
-                // surrounding messages.
-                padding: const EdgeInsetsDirectional.only(
-                  end: 5, top: verticalPadding, bottom: verticalPadding),
-                child: Container(
-                  // Inner padding preserves whitespace even when the text's
-                  // width approaches the button's min-width (e.g. because
-                  // there are more than three digits).
-                  padding: const EdgeInsets.symmetric(horizontal: 4),
-                  decoration: BoxDecoration(
-                    color: theme.colorPollVoteCountBackground,
-                    border: Border.all(color: theme.colorPollVoteCountBorder),
-                    borderRadius: BorderRadius.circular(3)),
-                  child: Center(
-                    child: Text(option.voters.length.toString(),
-                      style: textStyleBold.copyWith(
-                        color: theme.colorPollVoteCountText, fontSize: 20))))))),
+          ConstrainedBox(
+            constraints: const BoxConstraints(minWidth: 44, minHeight: 44),
+            child: Padding(
+              // For accessibility, the touch target is padded to be larger
+              // than the vote count box.  Still, we avoid padding at the
+              // start because we want to align all the poll options to the
+              // surrounding messages.
+              padding: const EdgeInsetsDirectional.only(
+                end: 5, top: verticalPadding, bottom: verticalPadding),
+              child: Material(
+                shape: RoundedRectangleBorder(
+                  borderRadius: BorderRadius.circular(3),
+                  side: BorderSide(color: theme.colorPollVoteCountBorder)),
+                color: theme.colorPollVoteCountBackground,
+                clipBehavior: Clip.antiAlias,
+                child: InkWell(
+                  onTap: () => _toggleVote(option),
+                  child: Padding(
+                    // Inner padding preserves whitespace even when the text's
+                    // width approaches the button's min-width (e.g. because
+                    // there are more than three digits).
+                    padding: const EdgeInsets.symmetric(horizontal: 4),
+                    child: Center(
+                      child: Text(option.voters.length.toString(),
+                        style: textStyleBold.copyWith(
+                          color: theme.colorPollVoteCountText, fontSize: 20)))))))),
           Expanded(
             child: Padding(
               // This and the padding on the vote count box both extend the row