[fix] TextInput remove default browser margin

Close #1458

Author: chrisdrackett

packages/react-native-web/src/exports/TextInput/index.js

@@ -321,6 +321,7 @@ const classes = css.create({
     borderRadius: 0,
     boxSizing: 'border-box',
     font: '14px System',
+    margin: 0,
     padding: 0,
     resize: 'none'
   }