Make it so that encapsulation for empty styles, styles containing only whitespace and comments, etc.
is handled the same way as with no styles at all.
Components without styles already have view encapsulation set to `None`
to avoid generating unnecessary attributes for style scoping, like `_ngcontent-ng-c1` (#27175)
If the component has an empty external styles file instead, the compiler would generate
a component definition without the `styles` field, but still using the default encapsulation.
This can result in runtime overhead if the developer forgets to delete the empty styles file
generated automatically for new components by Angular CLI.
Closes#16602
PR Close#57130
97fb86d331