fix(init/pwsh): preserve ViModeChangeHandler (#6225)

* Combine ViModeChangeHandler

If a user has defined a ViModeChangeHandler setting this would respect that as well as redraw the prompt (to allow rendering things like the character change).

* Add newline

* Use call operator to limit new closure scope

* Pass any args to original handler

src/init/starship.ps1

@@ -211,9 +211,21 @@ $null = New-Module starship {
     )
 
     try {
+        # Combine user defined ViModeChangeHandler if it exists
+        if((Get-PSReadLineOption).ViModeChangeHandler){
+            # &{...} to limit the scope of the GetNewClosure
+            & {
+                $originalHandler = (Get-PSReadLineOption).ViModeChangeHandler
+                Set-PSReadLineOption -ViModeChangeHandler {
+                    [Microsoft.PowerShell.PSConsoleReadLine]::InvokePrompt()
+                    & $originalHandler @args
+                }.GetNewClosure()
+            }
+        } else {
             Set-PSReadLineOption -ViModeIndicator script -ViModeChangeHandler {
                 [Microsoft.PowerShell.PSConsoleReadLine]::InvokePrompt()
             }
+        }
     } catch {}
 
     Export-ModuleMember -Function @(