implement useImportAccount and useExportAccount with progress display

[estebanabaroa]

the API should be something like

export interface UseImportAccountOptions extends Options {
  account?: string
   // let the user not import votes, comments, edits if they dont want, since it's slow, all default to true
  votes?: boolean
  comments?: boolean
  edits?: boolean
}
export interface UseImportAccountResult extends Result {
  importedAccount: Account | undefined
  importAccount(): Promise<void>
  // use these numbers to display progress, importing is slow so must display progress
  // if votes, comments or edits option is false, count should be 0
  voteCount: number
  importedVoteCount: number
  commentCount: number
  importedCommentCount: number
  editCount: number
  importedEditCount: number
}

export interface UseExportAccountOptions extends Options {
   // let the user not import votes, comments, edits if they dont want, since it's slow, all default to true
  votes?: boolean
  comments?: boolean
  edits?: boolean
}
export interface UseExportAccountResult extends Result {
  exportedAccount: string | undefined
  exportAccount(): Promise<void>
  // use these numbers to display progress, importing is slow so must display progress
  // if votes, comments or edits option is false, count should be 0
  voteCount: number
  importedVoteCount: number
  commentCount: number
  importedCommentCount: number
  editCount: number
  importedEditCount: number
}