Reduce count of `require` for `url`

[alexander-akait]

• Operating System: no matter
• Node Version: no matter
• NPM Version: no matter
• webpack Version: no matter
• css-loader Version: 1.0.1

Feature Proposal

On each url we generate require, but we can avoid this move require on top and avoid extra require for duplicate assets in CSS.

Feature Use Case

Less require - better performance.