Move turf require inside GET_VECTOR_INFO reducer

[manisandro]

This allows the turf modules to be ignored when creating the webpack bundle by adding

new webpack.IgnorePlugin(/^(turf*)$/)

to the plugins in webpack.config.js, saving around 0.5 MB from the resulting optimized build (mostly thanks to not pulling in the jsts modules). This clearly implies that the application promises to never attempt to identify a vector layer feature.

[coveralls]

Coverage increased (+0.09%) to 80.271% when pulling df92474 on sourcepole:turf into bdeb615 on geosolutions-it:master.