List the Books instances you can act on

Lists the Books instances, i.e. organizations' books (their general ledger: chart of accounts, journal entries, and reports), that this token can act on. Call this first, then pass an instance's booksId as the booksId argument of the other Books operations, such as the list ledgers endpoint (getBooksLedgers). A token can only act on its own organization's Books instance, so this lists at most that one instance; where booksId is optional, the token may omit it. Each instance has its booksId; the organizationId, companyName, and callsign of the organization it belongs to; and its relationship to the token's organization, which is self. Lists exactly the instances the other Books operations would let this token act on, given the scopes those operations need: the token's user must be an active member of the instance's organization with permission to manage Books, code transactions, and manage accounting integrations, and with access to all of its accounts, and the organization must have access to Books. An empty list means there is no instance this token can act on. Instances are sorted by companyName, ignoring case, and returned a page at a time: when the response has a nextPageToken, pass it as pageToken to get the next page.