Substitute use of IsPathFullyQualified to restore Windows PowerShell compatibility

[joshooaj]

Description

The Initialize-PSBuild function was not compatible with .NET Framework / PowerShell 5.1 due to the use of the System.IO.Path.IsPathFullyQualified() method, introduced with the fix for #27. I changed the function to check if the value of OutDir already started with BHProjectPath rather than testing if OutDir was a fully qualified path on its own.

This seems to have solved the issue and tests are passing. Also, changing the value of $PSBPreference.Build.OutDir seems to result in the same behavior before and after the change introduced in this PR, though I don't think any tests were introduced to specifically test the original fix so I'm not 100% certain this is the best solution.

Related Issue

Issue #53

Motivation and Context

I still regularly work with PowerShell 5.1 due to legacy .NET Framework dependencies that I'm required to use. I began to use the Stucco module for setting up my modules, but I cannot call .\build.ps1 from Windows PowerShell because the PowerShellBuild Initialize-PSBuild command calls a method that is not available in .NET Framework. I am now using this modified version of PowerShellBuild.

How Has This Been Tested?

I verified that I can build modules using the Stucco template on Windows using Windows PowerShell, and PowerShell 7, as well as Ubuntu on WSL2 using PowerShell 7. I tested these builds with and without a custom $PSBPreference.Build.OutDir value set in my psakefile.

Types of changes

• [x] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• [x] My code follows the code style of this project.
• [ ] My change requires a change to the documentation.
• [ ] I have updated the documentation accordingly.
• [x] I have read the CONTRIBUTING document.
• [ ] I have added tests to cover my changes.
• [x] All new and existing tests passed.

[HeyItsGilbert]

I was using a dummy VM for a demo (on how to use Stucco) and it looks like I ran into the same issue.

[devblackops]

Thanks for the fix @joshooaj!