Improve rendering of project or subject lists

[adswa]

When I call datalad xnat-init without a project specification or datalad xnat-update without a subject specification, the resulting list of available projects/subjects can flood the terminal if it is a large server or project.

datalad -c datalad.credentials.force-ask=1 xnat-init https://xnat.kube.fz-juelich.de                        1 !
You need to authenticate with 'xnat.kube.fz-juelich.de' credentials. https://xnat.kube.fz-juelich.de/app/template/Register.vm provides information on how to gain access
user: a.wagner

password: 
password (repeat): 
No project name specified. The following projects are available on https://xnat.kube.fz-juelich.de for user a.wagner:
  1000BRAINS
  3T_invivo
  4T_invivo
  7T_Neuner
  7T_clinical
  7T_invivo
  9komma4
  DINH
  INM1_CON100
  INM1_DTAGE
  INM1_DTAGE2
  INM1_INCAGE
  INM3_AMATE-Z
  INM3_CC
  INM3_Connect
  INM3_INDU
  INM3_ITHFA
  INM3_JA
  INM3_OMEGA
  INM3_PIRCEM
  INM3_Reversal
  INM3_SORELOX
  INM3_SRT-Age
  INM3_SRT-fAge
  INM7_MOVIES
  MNI
  Pharmacophore1
  QA
  QUANT_NOT
  TB1
  TQA
  X_CC
  animal
  chervakov
  jmauler
  kmoellenhoff
  mr_contrast
  mr_diff
  mr_hw
  mr_pet
  mr_phase
  mr_qi
  mr_seq
  mschwerter
  phantoms
  postmortem
  rbuschbeck
  rtfmri_phg
  shaddo1
  shaddo2
  wworthoff
  zabbas

or for update:

datalad xnat-update
The following subjects are available for XNAT project animal:
 XNATINM4_S02823
 XNATINM4_S02899
 XNATINM4_S02908
 XNATINM4_S02909
 XNATINM4_S02914
 XNATINM4_S03893
 XNATINM4_S03895
 XNATINM4_S03896
 XNATINM4_S03951
 XNATINM4_S03952
 XNATINM4_S03967
 XNATINM4_S03986
 XNATINM4_S04068
 XNATINM4_S04081
 XNATINM4_S04161
 XNATINM4_S04164
 XNATINM4_S04169
 XNATINM4_S04191
 XNATINM4_S04198
 XNATINM4_S04199
 XNATINM4_S04281
 XNATINM4_S04282
 XNATINM4_S04284
 XNATINM4_S04338
 XNATINM4_S04383
 XNATINM4_S04406
 XNATINM4_S04407
 XNATINM4_S04412
 XNATINM4_S04457
 XNATINM4_S04463
 XNATINM4_S04464
 XNATINM4_S04473
 XNATINM4_S04474
 XNATINM4_S04475
 XNATINM4_S04476
 XNATINM4_S04503
 XNATINM4_S04511
 XNATINM4_S04518
 XNATINM4_S04531
 XNATINM4_S04543
 XNATINM4_S04764
 XNATINM4_S04771
 XNATINM4_S04772
 XNATINM4_S04773
 XNATINM4_S04779
 XNATINM4_S04789
 XNATINM4_S04805
 XNATINM4_S04822
 XNATINM4_S04838
 XNATINM4_S04852
 XNATINM4_S04875
 XNATINM4_S04880
 XNATINM4_S04889
 XNATINM4_S04893
 XNATINM4_S04912
 XNATINM4_S04928
 XNATINM4_S04948
 XNATINM4_S04961
 XNATINM4_S04964
 XNATINM4_S04968
 XNATINM4_S04970
 XNATINM4_S04973
 XNATINM4_S04991
 XNATINM4_S04992
 XNATINM4_S05012
 XNATINM4_S05017
 XNATINM4_S05025
 XNATINM4_S05028
 XNATINM4_S05094
 XNATINM4_S05095
 XNATINM4_S05102
 XNATINM4_S05110
 XNATINM4_S05111
 XNATINM4_S05112
 XNATINM4_S05143
 XNATINM4_S05147
 XNATINM4_S05152
 XNATINM4_S05153
 XNATINM4_S05158
 XNATINM4_S05162
 XNATINM4_S05163
 XNATINM4_S05211
 XNATINM4_S05220
 XNATINM4_S05226
 XNATINM4_S05228
 XNATINM4_S05232
 XNATINM4_S05235
 XNATINM4_S05238
 XNATINM4_S05252
 XNATINM4_S05257
 XNATINM4_S05258
 XNATINM4_S05263
 XNATINM4_S05271
 XNATINM4_S05276
 XNATINM4_S05281
 XNATINM4_S05297
 XNATINM4_S05305
 XNATINM4_S05307
 XNATINM4_S05324
 XNATINM4_S05326
 XNATINM4_S05333
 XNATINM4_S05340
 XNATINM4_S05368
 XNATINM4_S05459
 XNATINM4_S05471
 XNATINM4_S05481
 XNATINM4_S05495
 XNATINM4_S05507
 XNATINM4_S05516
 XNATINM4_S05520
 XNATINM4_S05541
 XNATINM4_S05563
 XNATINM4_S05573
 XNATINM4_S05578
 XNATINM4_S05591
 XNATINM4_S05595
 XNATINM4_S05599
 XNATINM4_S05788
 XNATINM4_S05789
 XNATINM4_S05790
 XNATINM4_S05791
 XNATINM4_S05792
 XNATINM4_S05793
 XNATINM4_S05794
 XNATINM4_S05795
 XNATINM4_S05796
 XNATINM4_S05797
 XNATINM4_S05798
 XNATINM4_S05799
 XNATINM4_S05800
 XNATINM4_S05801
 XNATINM4_S05802
 XNATINM4_S05803
 XNATINM4_S05804
 XNATINM4_S05809
 XNATINM4_S05810
 XNATINM4_S05811
 XNATINM4_S05812
 XNATINM4_S05813
 XNATINM4_S05814
 XNATINM4_S05815
 XNATINM4_S05816
 XNATINM4_S05817
 XNATINM4_S05818
 XNATINM4_S05819
 XNATINM4_S05955
 XNATINM4_S06092
 XNATINM4_S06238
 XNATINM4_S06743
Specify a specific subject(s) or "all" to download associated files for.

I wonder if we can make this rendering more clever. Maybe with a datalad xnat-* --report argument that returns this list and doesn't otherwise.
What would be really amazing to have is a prompt that lets me select the project or subject to init/update.

[adswa]

After a quick discussion in gathertown, I'll try to implement an interactive picker

[mih]

See #64