New endpoint: /objectbrowser/import

Allows importing of objects from a CSV style input

* New view /objectbrowser/import
* Added link to "top-right-cogwheel" called "import objects"
* Primitive duplication support (i.e. refuses to import objects already in config)
* Allows preview of what will be saved

Fixes #382
Merge pull request #483 from opinkerfi/feature-import-objects

New endpoint: /objectbrowser/import