feat: upgrate to new theme (#2027)

Co-authored-by: Himself65 <himself65@outlook.com>

packages/component/src/ui/popper/PopoverArrow.tsx

@@ -92,6 +92,6 @@ const StyledArrow = styled('span')<{
       bottom: 0,
     },
 
-    ...getArrowStyle(placement, theme.colors.tooltipBackground),
+    ...getArrowStyle(placement, 'var(--affine-tooltip)'),
   };
 });

packages/component/src/ui/popper/Popper.tsx

@@ -191,6 +191,6 @@ export const BasicStyledPopper = styled(PopperUnstyled, {
   zIndex?: CSSProperties['zIndex'];
 }>(({ zIndex, theme }) => {
   return {
-    zIndex: zIndex ?? theme.zIndex.popover,
+    zIndex: zIndex ?? 'var(--affine-z-index-popover)',
   };
 });