Only load file into GCODE viewer when that is actually visible
Only load file into GCODE viewer when that is actually visible

Reduces needed bandwidth on page load, might help to mitigate
bandwidth related issues described in #1241.

beeverycreative/BEEweb,Salandora/OctoPrint,Salandora/OctoPrint,bicephale/OctoPrint,foosel/OctoPrint,foosel/OctoPrint,bicephale/OctoPrint,JackGavin13/octoprint-test-not-finished,JackGavin13/octoprint-test-not-finished,Jaesin/OctoPrint,Jaesin/OctoPrint,Salandora/OctoPrint,beeverycreative/BEEweb,foosel/OctoPrint,beeverycreative/BEEweb,Jaesin/OctoPrint,JackGavin13/octoprint-test-not-finished,bicephale/OctoPrint,beeverycreative/BEEweb,Jaesin/OctoPrint,JackGavin13/octoprint-test-not-finished,Salandora/OctoPrint,bicephale/OctoPrint,foosel/OctoPrint