V2.3.2 (#620)

* Refactor camera component to ./src/camera

 - Refactor camera component to ./src/camera from ./src/html5-qrcode.ts

* Misc fixes (codacy)

* Codacy fixes

* (refactor) Abstract camera selection UI to a separate class

* Add support for zoom slider

And misc changes.

* misc fixes.

* Misc changes per PR comments.

* Update change log + codacy fix.

* Update html5-qrcode.min.js

* Add unit test for camera-selection-ui and camera-zoom-ui

* Refactor TorchButton and remove html5qrcode deps

To make it feasible to test the class.

* Create torch-button.test.ts

* Update torch-button.test.ts

* Make supportedScanTypes optional.

README.md

@@ -554,7 +554,7 @@ interface Html5QrcodeScannerConfig
    *    - [SCAN_TYPE_FILE] - Only file based scan supported.
    *  - Setting wrong values or multiple values will fail.
    */
-  supportedScanTypes: Array<Html5QrcodeScanType> | [];
+  supportedScanTypes?: Array<Html5QrcodeScanType> | [];
 
   /**
    * If {@code true} the rendered UI will have button to turn flash on or off 

src/html5-qrcode-scanner.ts

@@ -114,7 +114,7 @@ interface Html5QrcodeScannerConfig
      *    - [SCAN_TYPE_FILE] - Only file based scan supported.
      *  - Setting wrong values or multiple values will fail.
      */
-    supportedScanTypes: Array<Html5QrcodeScanType> | [];
+    supportedScanTypes?: Array<Html5QrcodeScanType> | [];
 
     /**
      * If {@code true} the rendered UI will have button to turn flash on or off

src/ui/scanner/scan-type-selector.ts

@@ -17,7 +17,7 @@ import {
 export class ScanTypeSelector {
     private supportedScanTypes: Array<Html5QrcodeScanType>;
 
-    constructor(supportedScanTypes: Array<Html5QrcodeScanType> | []) {
+    constructor(supportedScanTypes?: Array<Html5QrcodeScanType> | []) {
         this.supportedScanTypes = this.validateAndReturnScanTypes(
             supportedScanTypes);
     }