Perfomance improvements (mostly in WLJS Interpreter, removed a lot of logging and outdated APIs), new UI features, better support of WL functions

Minor changes in UI and Graphics3D and massive changes in possibilities of exporting notebooks.

We fixed a few bugs in 2D math input and cursor navigations, added new features to markdown editor and added new export feature for individual figures used in the notebook. We also did refactor the code base of all cell types and in the editor.

Breaking changes: please, update your client using binaries from this release

We reworked our main application on Windows, cleaned up UI and introduced a few new modes.