message: feat(GUI): add webview api version parameter
  We add the API version sent to the banner via a GET search parameter,
  allowing for more intricate control over what data needs or can be sent.
diff: @@ -30,20 +30,42 @@ const MODULE_NAME = 'Etcher.Components.SafeWebview';
  const angularSafeWebview = angular.module(MODULE_NAME, []);
  /**
  - * @summary GET parameter sent to the initial webview source URL
  + * @summary Electron session identifier
  * @constant
  * @private
  * @type {String}
  */
  -const VERSION_PARAM = 'etcher-version';
  +const ELECTRON_SESSION = 'persist:success-banner';
  /**
  - * @summary Electron session identifier
  + * @summary Etcher version search-parameter key
  * @constant
  * @private
  * @type {String}
  */
  -const ELECTRON_SESSION = 'persist:success-banner';
  +const ETCHER_VERSION_PARAM = 'etcher-version';
  +
  +/**
  + * @summary API version search-parameter key
  + * @constant
  + * @private
  + * @type {String}
  + */
  +const API_VERSION_PARAM = 'api-version';
  +
  +/**
  + * @summary Webview API version
  + * @constant
  + * @private
  + * @type {String}
  + *
  + * @description
  + * Changing this number represents a departure from an older API and as such
  + * should only be changed when truly necessary as it introduces breaking changes.
  + * This version number is exposed to the banner such that it can determine what
  + * features are safe to utilize.
  + */
  +const API_VERSION = 1;
  /**
  * @summary Webviews that hide/show depending on the HTTP status returned
  @@ -67,8 +89,9 @@ class SafeWebview extends react.PureComponent {
  const url = new URL(props.src);
  - // We set the version GET parameter here.
  - url.searchParams.set(VERSION_PARAM, packageJSON.version);
  + // We set the version GET parameters here.
  + url.searchParams.set(ETCHER_VERSION_PARAM, packageJSON.version);
  + url.searchParams.set(API_VERSION_PARAM, API_VERSION);
  this.entryHref = url.href;
  