PSv5 backward compatibility for Invoke-WebRequest

[TinaMor]

PR description

What does this PR do

This PR fixes a backward compatibiltu issues with PowerShell v5.1. This version's Invoke-WebRequest command does not have the flags -MaximumRetryCount and -RetryIntervalSec.

Github issue

[BUG] [CTK v1.0.0] Install error with downloads #39

Relevant links

Invoke-WebRequest PSv5.1
Invoke-WebRequest PSv7.4 and above

Checklist

As part of our commitment to engineering excellence, before submitting this PR, please make sure:

• You've tested this code in both Desktop & Server environments and AMD & ARM64 enviroments (functional testing).
• You've added unit tests for new code.
• You've added/updated documentation in the cmdlet docs, command-reference.md and the modules help files.
• You've reviewed the PR/code best practices defined in the CONTRIBUTING.md.

In addition, after this PR has been reviewed, please agree to:

• If changes have been made to your PR in the process of addressing comments, please make sure to test again the final version in both AMD and ARM64 environments.
• Validate your changes have not introduced any regressions.

[CharityKathure]

Should manual retry logic be implemented instead of removing MaximumRetryCount and RetryIntervalSec to maintain retry while ensuring backward compatibility?

[CharityKathure]

LGTM