Bugfix - Test if InstalledScriptInfos folder exists and create if needed

[anamnavi]

Install-PSResource code was not checking if the InstalledScriptInfos folder existed, would try to use that path regardless and throw an uncaught error. This PR makes a fix to ensure the folder exists.

Fixes #1540

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• [ ] Summarized changes
• [ ] Make sure all .h, .cpp, .cs, .ps1 and .psm1 files have the correct copyright header
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