Add comprehensive test suite, fix minor issues, rename function and file names to match approved verbs (#708)

Scripts/FileIO/Import-JsonFile.ps1

@@ -0,0 +1,34 @@
+<#
+    .SYNOPSIS
+        Imports a JSON file, optionally validates its version, and returns $null on failure.
+#>
+function Import-JsonFile {
+    param (
+        [string]$filePath,
+        [string]$expectedVersion = $null,
+        [switch]$optionalFile
+    )
+    
+    if (-not (Test-Path $filePath)) {
+        if (-not $optionalFile) {
+            Write-Error "File not found: $filePath"
+        }
+        return $null
+    }
+    
+    try {
+        $jsonContent = Get-Content -Path $filePath -Raw | ConvertFrom-Json
+        
+        # Validate version if specified
+        if ($expectedVersion -and $jsonContent.Version -and $jsonContent.Version -ne $expectedVersion) {
+            Write-Error "$(Split-Path $filePath -Leaf) version mismatch (expected $expectedVersion, found $($jsonContent.Version))"
+            return $null
+        }
+        
+        return $jsonContent
+    }
+    catch {
+        Write-Error "Failed to parse JSON file: $filePath"
+        return $null
+    }
+}