fix: ensure parent directories are created in EnsureDirExists function

[matthisholleville]

Closes #

📑 Description

The previous implementation of the EnsureDirExists function only created a
single directory, which resulted in an error if the parent directories did
not exist. This fix updates the function to create parent directories
recursively using os.MkdirAll.

✅ Checks

• My pull request adheres to the code style of this project
• My code requires changes to the documentation
• I have updated the documentation as required
• All the tests have passed

ℹ Additional Information

[AlexsJones]

Great work