Update CLI for infinite questioning for a project name

The CLI should prompt the user for a project name repeatedly until a valid, non-existing folder name is provided. It should behave as follows:

```text
$ crawlee create
[?] Name of the new project folder: asd
Folder /home/vdusek/Projects/crawlee-py/asd already exists. Please choose another name.
[?] Name of the new project folder:
```