fix some result types and refactor types themselves

src/interfaces/common.ts

@@ -15,10 +15,6 @@ export interface GenericCredWrapper<T extends GenericVerifiableCredential> {
   publicUrls?: Record<string, string>;
 }
 
-export interface ResultWithType {
-  type: string;
-}
-
 export interface ErrorResponse {
   error?: {
     message?: string;
@@ -30,11 +26,6 @@ export interface InternalError {
   userMessage?: string;
 }
 
-export interface ErrorResult extends ResultWithType {
-  type: "error";
-  error: InternalError;
-}
-
 export interface KeyMeta {
   did: string;
   publicKeyHex: string;