Change hardcoded name to just Aether and/or remove hardcoding altogether

[KrisAphalon]

Similar to #23 (which I found only now, while creating this issue)

There are several cases in which folder name where the theme is installed is hardcoded, for example: https://github.com/NoiSek/Aether/blob/master/src/js/Logic/FileOperations.js#L16

I had problems with it and manual installation, that I've fixed after tinkering and looking at the source code (praise the open licenses) #72

Other default themes use simple names, such as simple or antegros. I think naming it aether or Aether would be more descriptive, as well as it would simplify changing config a bit. It would be consistent with git repository name as well.

Other possibility is to remove hardcoding altogether, but I don't know how doable it is, or how much work it would require.