Add log statements, add find_and_count function.
Add log statements, add find_and_count function.

  * find_and_count: used to retrieve documents in a collection and
    to count the total number of documents in the collection.

kernelci/kernelci-backend,joyxu/kernelci-backend,joyxu/kernelci-backend,joyxu/kernelci-backend,kernelci/kernelci-backend