feat: avoid opening the drawer if there's only one block

[cuquo]

Description

There's no need to open a drawer to select the only option available, in case there's only one block it will directly add it without having to do an extra step for the user.

• [x] I have read and understand the CONTRIBUTING.md document in this repository.

Type of change

• [ ] Chore (non-breaking change which does not add functionality)
• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [ ] Change to the templates directory (does not affect core functionality)
• [ ] Change to the examples directory (does not affect core functionality)
• [ ] This change requires a documentation update

Checklist:

• [ ] I have added tests that prove my fix is effective or that my feature works
• [x] Existing test suite passes locally with my changes
• [ ] I have made corresponding changes to the documentation