Steps to reproduce:
1. Open the attached user project "CustomPackageNameIssue.zip"
2. Export these packages
"com.cec.something.unitypackage"
"com.cec.something.extension.unitypackage"
3. Create a new project and import the exported packages
4. Observe the Console Error:
Failed to create folder structure: Packages/com.cec.something.extension

Expected results: Importing a custom package does not fail when the beginning of the name collides with another package
Actual Results: Importing a custom package fails when the beginning of the name collides with another package

Reproducible in: 2021.3.28f1, 2022.3.5f1, 2023.1.5f1, 2023.2.0b1, 2023.3.0a1

Environment tested on: Windows 10

Notes:
-If the beginning of the package is named "com.cec.somethinextension" then no errors appear