chore: adjust legacy space icon (#5886)

frontend/appflowy_flutter/lib/workspace/presentation/home/menu/sidebar/space/shared_widget.dart

@@ -500,7 +500,7 @@ class CurrentSpace extends StatelessWidget {
           SpaceIcon(
             dimension: 22,
             space: space,
-            svgSize: 13,
+            svgSize: 12,
             cornerRadius: 8.0,
           ),
           const HSpace(10),

frontend/appflowy_flutter/lib/workspace/presentation/home/menu/sidebar/space/space_icon.dart

@@ -39,9 +39,10 @@ class SpaceIcon extends StatelessWidget {
         height: dimension,
         color: color,
         child: Center(
-          child: svgSize == null
+          child:
-              ? svg
+              svgSize == null || space.spaceIcon?.contains('space_icon') == true
-              : SizedBox.square(dimension: svgSize!, child: svg),
+                  ? svg
+                  : SizedBox.square(dimension: svgSize!, child: svg),
         ),
       ),
     );

frontend/appflowy_flutter/lib/workspace/presentation/home/menu/sidebar/space/space_icon_popup.dart

@@ -119,6 +119,20 @@ class _SpaceIconPopupState extends State<SpaceIconPopup> {
                       dimension: 32,
                       iconDimension: 32,
                     );
+                  } else if (value.contains('space_icon')) {
+                    child = ClipRRect(
+                      borderRadius: BorderRadius.circular(widget.cornerRadius),
+                      child: Container(
+                        color: Color(int.parse(color)),
+                        child: Align(
+                          child: FlowySvg(
+                            FlowySvgData('assets/flowy_icons/16x/$value.svg'),
+                            size: const Size.square(42),
+                            color: Theme.of(context).colorScheme.surface,
+                          ),
+                        ),
+                      ),
+                    );
                   } else {
                     final content = kIconGroups?.findSvgContent(value);
                     if (content == null) {