message: ref(hub): Reduce hub bundle size
  Move field initializers inside constructor to reduce bundle size.
diff: @@ -44,28 +44,37 @@ const MAX_BREADCRUMBS = 100;
  */
  export class Scope implements ScopeInterface {
  /** Flag if notifying is happening. */
  - protected _notifyingListeners: boolean = false;
  + protected _notifyingListeners: boolean;
  /** Callback for client to receive scope changes. */
  - protected _scopeListeners: Array<(scope: Scope) => void> = [];
  + protected _scopeListeners: Array<(scope: Scope) => void>;
  /** Callback list that will be called after {@link applyToEvent}. */
  - protected _eventProcessors: EventProcessor[] = [];
  + protected _eventProcessors: EventProcessor[];
  /** Array of breadcrumbs. */
  - protected _breadcrumbs: Breadcrumb[] = [];
  + protected _breadcrumbs: Breadcrumb[];
  /** User */
  - protected _user: User = {};
  + protected _user: User;
  /** Tags */
  - protected _tags: { [key: string]: Primitive } = {};
  + protected _tags: { [key: string]: Primitive };
  /** Extra */
  - protected _extra: Extras = {};
  + protected _extra: Extras;
  /** Contexts */
  - protected _contexts: Contexts = {};
  + protected _contexts: Contexts;
  +
  + /** Attachments */
  + protected _attachments: Attachment[];
  +
  + /**
  + * A place to stash data which is needed at some point in the SDK's event processing pipeline but which shouldn't get
  + * sent to Sentry
  + */
  + protected _sdkProcessingMetadata: { [key: string]: unknown };
  /** Fingerprint */
  protected _fingerprint?: string[];
  @@ -86,14 +95,18 @@ export class Scope implements ScopeInterface {
  /** Request Mode Session Status */
  protected _requestSession?: RequestSession;
  - /** Attachments */
  - protected _attachments: Attachment[] = [];
  -
  - /**
  - * A place to stash data which is needed at some point in the SDK's event processing pipeline but which shouldn't get
  - * sent to Sentry
  - */
  - protected _sdkProcessingMetadata?: { [key: string]: unknown } = {};
  + public constructor() {
  + this._notifyingListeners = false;
  + this._scopeListeners = [];
  + this._eventProcessors = [];
  + this._breadcrumbs = [];
  + this._attachments = [];
  + this._user = {};
  + this._tags = {};
  + this._extra = {};
  + this._contexts = {};
  + this._sdkProcessingMetadata = {};
  + }
  /**
  * Inherit values from the parent scope.
  