fix(core): replace most --affine with cssVar (#5728)

using a [babel plugin](https://gist.github.com/pengx17/49e24ae8a5a609bdaff122ee8c679d1c) to transform all var(--affine-xxx) to cssVar

Some issues:
- tried ast-grep but it seems to be not easy to add imports conditionally
- current work does not work well with ts with types because babel will strip them out

packages/frontend/component/src/ui/divider/style.css.ts

@@ -1,8 +1,8 @@
+import { cssVar } from '@toeverything/theme';
 import { style } from '@vanilla-extract/css';
-
 export const divider = style({
   height: '1px',
-  backgroundColor: 'var(--affine-border-color)',
+  backgroundColor: cssVar('borderColor'),
   borderRadius: '8px',
   margin: '8px 0',
   width: '100%',