Allow Enabling useCodeSnippetsOnMethodSuggest for JS As Well As TS (#16351)

Fixes #13952

**Bug**
The `typescript.useCodeSnippetsOnMethodSuggest` setting only applies to Typescript files. I believe it should also apply to JavaScript files.

**Fix**
Use `typescript.useCodeSnippetsOnMethodSuggest` to control this behavior for js files as well.

Also delete unused configuration file.

An alternate design would be to add a `javascript.useCodeSnippetsOnMethodSuggest` configuration option, if users really do want to have different behavior between JS and TS.

extensions/typescript/src/features/completionItemProvider.ts

@@ -5,7 +5,7 @@
 
 'use strict';
 
-import { CompletionItem, TextDocument, Position, CompletionItemKind, CompletionItemProvider, CancellationToken, WorkspaceConfiguration, TextEdit, Range, SnippetString } from 'vscode';
+import { CompletionItem, TextDocument, Position, CompletionItemKind, CompletionItemProvider, CancellationToken, WorkspaceConfiguration, TextEdit, Range, SnippetString, workspace } from 'vscode';
 
 import { ITypescriptServiceClient } from '../typescriptService';
 
@@ -87,7 +87,9 @@ export default class TypeScriptCompletionItemProvider implements CompletionItemP
 	}
 
 	public updateConfiguration(config: WorkspaceConfiguration): void {
-		this.config.useCodeSnippetsOnMethodSuggest = config.get(Configuration.useCodeSnippetsOnMethodSuggest, false);
+		// Use shared setting for js and ts
+		let typeScriptConfig = workspace.getConfiguration('typescript');
+		this.config.useCodeSnippetsOnMethodSuggest = typeScriptConfig.get(Configuration.useCodeSnippetsOnMethodSuggest, false);
 	}
 
 	public provideCompletionItems(document: TextDocument, position: Position, token: CancellationToken): Promise<CompletionItem[]> {
@@ -162,7 +164,7 @@ export default class TypeScriptCompletionItemProvider implements CompletionItemP
 					item.detail = Previewer.plain(detail.displayParts);
 				}
 
-				if (detail && this.config.useCodeSnippetsOnMethodSuggest && item.kind === CompletionItemKind.Function) {
+				if (detail && this.config.useCodeSnippetsOnMethodSuggest && (item.kind === CompletionItemKind.Function || item.kind === CompletionItemKind.Method)) {
 					let codeSnippet = detail.name;
 					let suggestionArgumentNames: string[];
 

extensions/typescript/src/features/configuration.ts

-/*---------------------------------------------------------------------------------------------
- *  Copyright (c) Microsoft Corporation. All rights reserved.
- *  Licensed under the MIT License. See License.txt in the project root for license information.
- *--------------------------------------------------------------------------------------------*/
-
-'use strict';
-
-import { workspace } from 'vscode';
-
-export interface IConfiguration {
-	useCodeSnippetsOnMethodSuggest?: boolean;
-}
-
-export var defaultConfiguration: IConfiguration = {
-	useCodeSnippetsOnMethodSuggest: false
-};
-
-export function load(myPluginId: string): IConfiguration {
-	let configuration = workspace.getConfiguration(myPluginId);
-
-	let useCodeSnippetsOnMethodSuggest = configuration.get('useCodeSnippetsOnMethodSuggest', defaultConfiguration.useCodeSnippetsOnMethodSuggest);
-
-	return {
-		useCodeSnippetsOnMethodSuggest
-	};
-}
\ No newline at end of file