Advanced color replace with color variables
#### Please tell us your OS and Sketch version when create issues.

- [x] Make sure you are using the latest version of [WeSketch](https://github.com/weixin/WeSketch)
- [x] OS Version: `macOS (11.4)`
- [x] Sketch Version: `74.1`

#### Issues below
Please add the ability to replace colors using Color Variables.
