WIP: Initial verison of the script editor

[keeshii]

This is implementation of the script editor integrated with the create app. This pull-request adds button next to "refresh-script", that opens a code editor in an overlay window. From there there is a possibility to spawn a web-entity for collaborative work.

This editor is still work in progress. Waiting for the changes in the CPP side.

[JulianGro]

I tried making CMake download the script editor assets as part of the build process, so we don't have all of these pre-compiled files in our main repository. See the patch (I also deleted the relevant assets in the interface/resources). I ran into an issue though, where Interface wouldn't load the file (in my case file:///~/html/script-editor/index.html). Other files in uncompressed resources like file:///~/serverless/tutorial.json can be loaded fine and I don't see any typo in the path.

I am just posting this here, so it doesn't get lost. In the patch I am loading from resources that weren't patched into the qrc; This is because we package the qrc directly from the source at configuration time, while the ExternalProject mechanism gets the assets at build time. To circumvent this, we could create a Python script that downloads the assets at configuration time, and then either put the assets into .gitignore or create the qrc from the build directory instead.