(PowerShellGH-1336) Add Code Folding settings and enable by default

Previously the syntax folding was available for all users.  However it was able
to be configured or turned off.  This commit adds a new `codeFolding` settings
section, with the syntax folding feature enabled by default.

Author: glennsarti

package.json

@@ -467,6 +467,11 @@
           "default": "",
           "description": "Specifies the path to a PowerShell Script Analyzer settings file. To override the default settings for all projects, enter an absolute path, or enter a path relative to your workspace."
         },
+        "powershell.codeFolding.enable": {
+          "type": "boolean",
+          "default": true,
+          "description": "Enables syntax based code folding. When disabled, the default indentation based code folding is used."
+        },
         "powershell.codeFormatting.preset": {
           "type": "string",
           "enum": [

src/features/Folding.ts

@@ -6,6 +6,7 @@ import {
 } from "vscode-languageclient";
 import { IFeature } from "../feature";
 import { Logger } from "../logging";
+import * as Settings from "../settings";
 
 /**
  * Defines a grammar file that is in a VS Code Extension
@@ -495,6 +496,9 @@ export class FoldingFeature implements IFeature {
     constructor(private logger: Logger, documentSelector: DocumentSelector) {
         const grammar: IGrammar = this.grammar(logger);
 
+        const settings = Settings.load();
+        if (!(settings.codeFolding && settings.codeFolding.enable)) { return; }
+
         // If the PowerShell grammar is not available for some reason, don't register a folding provider,
         // which reverts VSCode to the default indentation style folding
         if (grammar == null) {

src/settings.ts

@@ -29,6 +29,10 @@ export interface IBugReportingSettings {
     project: string;
 }
 
+export interface ICodeFoldingSettings {
+    enable?: boolean;
+}
+
 export interface ICodeFormattingSettings {
     preset: CodeFormattingPreset;
     openBraceOnSameLine: boolean;
@@ -72,6 +76,7 @@ export interface ISettings {
     scriptAnalysis?: IScriptAnalysisSettings;
     debugging?: IDebuggingSettings;
     developer?: IDeveloperSettings;
+    codeFolding?: ICodeFoldingSettings;
     codeFormatting?: ICodeFormattingSettings;
     integratedConsole?: IIntegratedConsoleSettings;
     bugReporting?: IBugReportingSettings;
@@ -109,6 +114,10 @@ export function load(): ISettings {
         powerShellExeIsWindowsDevBuild: false,
     };
 
+    const defaultCodeFoldingSettings: ICodeFoldingSettings = {
+        enable: true,
+    };
+
     const defaultCodeFormattingSettings: ICodeFormattingSettings = {
         preset: CodeFormattingPreset.Custom,
         openBraceOnSameLine: true,
@@ -150,6 +159,8 @@ export function load(): ISettings {
             configuration.get<IDebuggingSettings>("debugging", defaultDebuggingSettings),
         developer:
             getWorkspaceSettingsWithDefaults<IDeveloperSettings>(configuration, "developer", defaultDeveloperSettings),
+        codeFolding:
+            configuration.get<ICodeFoldingSettings>("codeFolding", defaultCodeFoldingSettings),
         codeFormatting:
             configuration.get<ICodeFormattingSettings>("codeFormatting", defaultCodeFormattingSettings),
         integratedConsole: