* add improvements TODO on creating book experience
* fix create book to support a more complex folder structure
* replace \\ to a forward slash on windows
* address pr comments
* fix tests
* use the posix version of path.sep
* Add dialog for creating books
* create empty book
* add localized constants
* add validation to dialog
* reset the create book command to original
* address pr comments
* change error message
* Init book toc manager in bookTreeView