message: fix(tracing): Add manual DOMStringList typing
diff: +/**
  + * A type returned by some APIs which contains a list of DOMString (strings).
  + *
  + * Copy DOMStringList interface so that user's dont have to include dom typings with Tracing integration
  + * Based on https://github.com/microsoft/TypeScript/blob/4cf0afe2662980ebcd8d444dbd13d8f47d06fcd5/lib/lib.dom.d.ts#L4051
  + */
  +interface DOMStringList {
  + /**
  + * Returns the number of strings in strings.
  + */
  + readonly length: number;
  + /**
  + * Returns true if strings contains string, and false otherwise.
  + */
  + contains(str: string): boolean;
  + /**
  + * Returns the string with index index from strings.
  + */
  + item(index: number): string | null;
  + [index: number]: string;
  +}
  +
  +declare var DOMStringList: {
  + prototype: DOMStringList;
  + new (): DOMStringList;
  +};
  +
  /**
  * The location (URL) of the object it is linked to. Changes done on it are reflected on the object it relates to.
  * Both the Document and Window interface have such a linked Location, accessible via Document.location and Window.location respectively.
  