Remove FindModule.ts since its long since been deprecated (#4228)

And the associated handlers in PSES do not exist.

Author: andyleejordan

package.json

@@ -229,7 +229,8 @@
       {
         "command": "PowerShell.PowerShellFindModule",
         "title": "Find/Install PowerShell Modules from the Gallery",
-        "category": "PowerShell"
+        "category": "PowerShell",
+        "deprecationMessage": "This feature is no longer available, we're sorry!"
       },
       {
         "command": "PowerShell.ShowAdditionalCommands",

src/features/FindModule.ts

@@ -12,7 +12,6 @@ import { ExamplesFeature } from "./features/Examples";
 import { ExpandAliasFeature } from "./features/ExpandAlias";
 import { ExtensionCommandsFeature } from "./features/ExtensionCommands";
 import { ExternalApiFeature, IPowerShellExtensionClient } from "./features/ExternalApi";
-import { FindModuleFeature } from "./features/FindModule";
 import { GenerateBugReportFeature } from "./features/GenerateBugReport";
 import { GetCommandsFeature } from "./features/GetCommands";
 import { HelpCompletionFeature } from "./features/HelpCompletion";
@@ -159,7 +158,6 @@ export async function activate(context: vscode.ExtensionContext): Promise<IPower
         new ExpandAliasFeature(),
         new GetCommandsFeature(logger),
         new ShowHelpFeature(),
-        new FindModuleFeature(),
         new ExtensionCommandsFeature(logger),
         new NewFileOrProjectFeature(),
         new RemoteFilesFeature(),