Replace icon export workflow and add exact WinGet icon fallback (#4522)

* Backup original screenshot_database.xlsx from Google docs

* Replace icon update workflow with PowerShell exporter

* Add exact WinGet icon lookup fallback

Author: mamoreau-devolutions

.github/workflows/update-icons.yaml

@@ -13,7 +13,6 @@ vcredist.exe
 unigetui_bin/
 APIKEY.txt
 *.pyc
-WebBasedData/screenshot_database.xlsx
 WebBasedData/new_urls.txt
 WebBasedData/screenshot-database.json.backup
 pr_body.md