fix #1393: Always use local help to return cmdlet help text

If the user has overridden the Get-Help -Online parameter to always be
true, then calls to Get-Help will always launch a new browser window
to the cmdlet help. Instead, we want it to return the full cmdlet text
as intended.

fix 1393: Always use local help when retrieving Full help

Author: deadlydog

src/PowerShellEditorServices/Services/PowerShellContext/Handlers/ShowHelpHandler.cs

@@ -62,7 +62,7 @@ public async Task<Unit> Handle(ShowHelpParams request, CancellationToken cancell
                     [System.Net.ServicePointManager]::SecurityProtocol = $oldSslVersion
                 }
 
-                return Microsoft.PowerShell.Core\Get-Help $CommandName -Full
+                return Microsoft.PowerShell.Core\Get-Help $CommandName -Full -Online:$false
                 ";
 
             string helpParams = request.Text;

src/PowerShellEditorServices/Services/PowerShellContext/Utilities/CommandHelpers.cs

@@ -139,6 +139,7 @@ public static async Task<string> GetCommandSynopsisAsync(
                 // We use .Name here instead of just passing in commandInfo because
                 // CommandInfo.ToString() duplicates the Prefix if one exists.
                 .AddParameter("Name", commandInfo.Name)
+                .AddParameter("Online", false)
                 .AddParameter("ErrorAction", "Ignore");
 
             var results = await powerShellContext.ExecuteCommandAsync<PSObject>(command, sendOutputToHost: false, sendErrorToHost: false).ConfigureAwait(false);