Turn the Install category filters into toggle chips (#4926)

* Turn the Install category filters into toggle chips

- Replace the filter buttons with toggles that show which ones are active
- Add ctrl click to select more than one category
- Keep the search box and the category filter independent of each other
- Expand matching categories while a filter is active

* Fix the filter interactions the category chips missed

- Pass the selected categories to the lazy rendering batches, the old call
  used a parameter that no longer exists and threw while typing
- Keep the category filter when switching tabs, the chips stayed checked
  while the filter itself was dropped
- Put a category back to collapsed once the filter that expanded it is gone

* Document the Install category filters

- Add a guide section for the chips, ctrl click and clearing the filter
- Note that search and the category chips apply together

* Correct the category filter guide wording

- Clearing by clicking the chip only applies when it is the only one selected
- Only categories with matches expand, and only auto expanded ones re-collapse

functions/private/Start-WinUtilInstallAppRendering.ps1

@@ -8,8 +8,14 @@ function Invoke-WinUtilInstallAppRenderBatch {
         $sync.$appKey = Initialize-InstallAppEntry -TargetElement $CategoryBatch.TargetElement -AppKey $appKey
     }
 
-    if ($sync.currentTab -eq "Install" -and $sync.SearchBar -and -not [string]::IsNullOrWhiteSpace($sync.SearchBar.Text)) {
-        Find-AppsByNameOrDescription -SearchString $sync.SearchBar.Text -Category $sync.SearchBar.Tag
+    # Entries render in batches, so a filter that is already active has to be applied to each new
+    # batch. Categories count as an active filter just like search text does.
+    if ($sync.currentTab -eq "Install" -and $sync.SearchBar) {
+        $selectedCategories = if ($sync.SelectedAppCategories) { $sync.SelectedAppCategories.ToArray() } else { @() }
+
+        if (-not [string]::IsNullOrWhiteSpace($sync.SearchBar.Text) -or $selectedCategories.Count -gt 0) {
+            Find-AppsByNameOrDescription -SearchString $sync.SearchBar.Text -Categories $selectedCategories
+        }
     }
 }