New+ Rename and Desktop icon positioning improvements (#48083)

New+ Rename and Desktop icon positioning improvements. Manually tested
on Windows 11. Windows 10 updates have NOT been tested.

## Summary of the Pull Request
* Obtain cursor position early in the lifecycle of the context menu
* Busy wait until copy is complete and shell is aware of icon
* If context menu is on desktop, reposition the icon using the cursor
position obtained scaled using monitor appropriate DPI
* Slight refactor to help port code from New++ to New+

## PR Checklist
- [x] Closes: #36440
- [ ] **Communication:** I've discussed this with core contributors
already. If the work hasn't been agreed, this work might be rejected
- [ ] **Tests:** Added/updated and all pass
- [n/a] **Localization:** All end-user-facing strings can be localized
- [n/a] **Dev docs:** Added/updated
- [n/a] **New binaries:** Added on the required places
- [n/a] [JSON for
signing](https://github.com/microsoft/PowerToys/blob/main/.pipelines/ESRPSigning_core.json)
for new binaries
- [n/a] [WXS for
installer](https://github.com/microsoft/PowerToys/blob/main/installer/PowerToysSetup/Product.wxs)
for new binaries and localization folder
- [n/a] [YML for CI
pipeline](https://github.com/microsoft/PowerToys/blob/main/.pipelines/ci/templates/build-powertoys-steps.yml)
for new test projects
- [n/a] [YML for signed
pipeline](https://github.com/microsoft/PowerToys/blob/main/.pipelines/release.yml)
- [n/a] **Documentation updated:** If checked, please file a pull
request on [our docs
repo](https://github.com/MicrosoftDocs/windows-uwp/tree/docs/hub/powertoys)
and link it here: #xxx

## Detailed Description of the Pull Request / Additional comments
* n/a

## Validation Steps Performed

**Windows 11**
* x64: Manually tested
* ARM64: Not tested

**Windows 10**
* Not tested

---------

Co-authored-by: Boliang Zhang (from Dev Box) <bozhang@microsoft.com>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 41b6b39b-b620-4e02-b7ca-8ae470a9c1e2

.github/actions/spell-check/allow/code.txt

@@ -171,6 +171,7 @@ thmutil
 uriutil
 VKTAB
 wcautil
+wcsnlen
 winkey
 wininet
 WMKEYDOWN
@@ -452,3 +453,7 @@ WIDGETBOARD
 
 # URIs
 actioncenter
+
+# New+ shell PIDL type names
+PCUITEMID
+PITEMID