Add bulk find/replace rename for selected policies/apps

[Copilot]

Renaming in Intune Toolkit was limited to a single selected item, making common prefix/word updates across multiple policies tedious. This change adds a bulk rename path that applies find/replace across selected policy/app names while preserving existing single-item edit behavior.

• Bulk rename flow (multi-select)

  • Added a SelectedItems.Count -gt 1 path in Scripts/RenameButton.ps1.
  • Prompts for find and replace text, confirms intent, then applies rename to each selected item.
  • Supports text removal by allowing empty replacement.
  • Uses case-insensitive matching/replacement and reports Renamed / Skipped / Failed totals at completion.

• Single-item flow remains intact

  • Existing one-item rename + description update flow is unchanged in behavior.
  • Shared policy name field and PATCH endpoint resolution were extracted into small helpers to avoid drift between single and bulk paths.

• Operational diagnostics

  • Added explicit skip/failure logging for bulk operations, including unavailable-name cases and attempted name transitions.

• Docs update

  • Updated README feature text to reflect single-item edit plus bulk find/replace rename support.

if ($selectedPolicies.Count -gt 1) {
    $findText = $findTextInput.Trim()
    $newName = [System.Text.RegularExpressions.Regex]::Replace(
        $currentName,
        [System.Text.RegularExpressions.Regex]::Escape($findText),
        [System.Text.RegularExpressions.MatchEvaluator]{ param($match) $replaceText },
        [System.Text.RegularExpressions.RegexOptions]::IgnoreCase
    )
}

• Fixes [Feature] Rename multiple policy names #62