feat(minifier): add RemoveUnusedCode

Author: Boshen

tasks/minsize/minsize.snap

@@ -21,7 +21,7 @@ Original   | minified   | minified   | gzip       | gzip       | Fixture
 
 3.20 MB    | 1.01 MB    | 1.01 MB    | 332.13 kB  | 331.56 kB  | echarts.js
 
-6.69 MB    | 2.32 MB    | 2.31 MB    | 493.00 kB  | 488.28 kB  | antd.js   
+6.69 MB    | 2.32 MB    | 2.31 MB    | 493.01 kB  | 488.28 kB  | antd.js   
 
 10.95 MB   | 3.51 MB    | 3.49 MB    | 910.06 kB  | 915.50 kB  | typescript.js