♻️ REFACTOR: Storage info flag statistics -> detailed

[chrisjsewell]

The statistics keyword and CLI flag is not really descriptive of its purpose (particularly after recent changes).
verdi storage info already gives statistics, then the flag simply generates more detailed information.

As an example:

$ verdi storage info
entities:
  Users:
    count: 4
  Computers:
    count: 14
  Nodes:
    count: 109521
  Groups:
    count: 5
  Comments:
    count: 0
  Logs:
    count: 0
  Links:
    count: 159848
repository:
  SHA-hash algorithm: sha256
  Compression algorithm: zlib+1

$ verdi storage info --detailed
entities:
  Users:
    count: 4
    emails:
    - a@b.com
    - aiida@theossrv2.epfl.ch
    - aiida@theossrv5.epfl.ch
    - xxx@epfl.ch
  Computers:
    count: 14
    labels:
    - bellatrix
    - brisi
    - 'daint (Imported #1)'
    - daint-gpu
    - daint-mc
    - daint_aprun
    - daint_mc
    - 'daint_mc (Imported #0)'
    - daint_old
    - dora
    - dora_aprun
    - localhost
    - theospc14-direct_
    - theospc27slurm
  Nodes:
    count: 109521
    node_types:
    - data.Data.
    - data.array.kpoints.KpointsData.
    - data.core.array.ArrayData.
    - data.core.array.bands.BandsData.
    - data.core.array.trajectory.TrajectoryData.
    - data.core.cif.CifData.
    - data.core.code.Code.
    - data.core.dict.Dict.
    - data.core.folder.FolderData.
    - data.core.remote.RemoteData.
    - data.core.singlefile.SinglefileData.
    - data.core.structure.StructureData.
    - data.core.upf.UpfData.
    - data.forceconstants.ForceconstantsData.
    - process.calculation.calcfunction.CalcFunctionNode.
    - process.calculation.calcjob.CalcJobNode.
    process_types:
    - aiida.calculations:codtools.ciffilter
    - aiida.calculations:quantumespresso.matdyn
    - aiida.calculations:quantumespresso.ph
    - aiida.calculations:quantumespresso.pw
    - aiida.calculations:quantumespresso.q2r
  Groups:
    count: 5
    type_strings:
    - core
    - core.import
  Comments:
    count: 0
  Logs:
    count: 0
  Links:
    count: 159848
repository:
  SHA-hash algorithm: sha256
  Compression algorithm: zlib+1
  Packs: 0
  Objects:
    unpacked: 199565
    packed: 0
  Size (MB):
    unpacked: 3734.387812614441
    packed: 0.0
    other: 0.01171875