Cleanup inline-styles with lightningcss for cleanupEnableBackground

[noahbald]

See the todo in cleanupEnableBackground

    /// Cleans up `enable-background`, unless document uses `<filter>` elements.
    ///
    /// Only cleans up attribute values
    /// TODO: Clean up inline-styles
    ///
    /// This job will:
    /// - Drop `enable-background` on `<svg>` node, if it matches the node's width and height
    /// - Set `enable-background` to `"new"` on `<mask>` or `<pattern>` nodes, if it matches the
    ///   node's width and height

We have context to provide styles now, and this would be preferrable to the current approach using regex