cli: support dir and glob pattern on download

[mvidalgarcia]

Depends on #483

Needs r-commons release to pass - reanahub/reana-commons#253

closes #402

To test

• Create a workflow
• Upload multiple files in multiple levels of directories
• Try to download different directories by name
• Try to download multiple files by passing glob patterns

Pseudo-example

$ reana-client download -w workflow 'mydir'
$ reana-client download -w workflow '**/*.py'
$ reana-client download -w workflow '**/*.txt'
$ reana-client download -w workflow 'mydir/foo/*.py'
...

If it the pattern matches more than one file, you should get a zip downloaded, otherwise a single file.

TBD

When downloading a single file, until now, the path where this file is in the workspace is respected locally. This is because the file is saved directly using the value that is passed to the command as an argument. E.g. reana-client download -w workflow foo/bar/myfile.txt would create directories foo/bar for you as it uses this argument to save the file.

After this PR, since the argument can be a glob pattern, we get the filename from the server-side and save it as it is, thus, causing the path where the file is not to be respected. This is done this way because otherwise, one might end up having folders called \*\* or similar. E.g. reana-client download -w workflow '**/myfile.txt' would create a dir called \*\* and put myfile.txt inside.

Update 19/04/2021: It is possible to pass attachment_filename arg to send_from_directory so one can customize the content of filename in the Content-Disposition header. Passing there a relative path allows us to keep the folder structure and be backwards compatible. Updated on https://github.com/reanahub/reana-workflow-controller/pull/369/files

[audrium]

Great work, tested it carefully and haven't spotted any issues 🚀

reana ❯ reana-client ls
NAME                                         SIZE     LAST-MODIFIED
fitdata/plot.png                             15450    2021-04-19T14:27:23
_yadage/yadage_snapshot_workflow.json        13274    2021-04-19T14:27:37
_yadage/yadage_workflow_instance.png         33777    2021-04-19T14:27:37
_yadage/yadage_workflow_instance.pdf         13928    2021-04-19T14:27:37
_yadage/yadage_workflow_instance.dot         1797     2021-04-19T14:27:37
code/gendata.C                               1937     2021-04-19T14:27:08
code/fitdata.C                               1648     2021-04-19T14:27:08
code/test.txt                                0        2021-04-19T14:32:03
gendata/data.root                            154859   2021-04-19T14:27:17
_yadage/adage/adagesnap.txt                  1337     2021-04-19T14:27:37
_yadage/adage/workflow.gif                   221433   2021-04-19T14:27:37
workflow/yadage/workflow-htcondorcern.yaml   2025     2021-04-19T14:27:08
workflow/yadage/workflow-slurmcern.yaml      1929     2021-04-19T14:27:08
workflow/yadage/workflow.yaml                1805     2021-04-19T14:27:08

~/Documents/projects/test
reana ❯ reana-client download 'code/*.C'
File download_2021-04-20-081952.zip downloaded to /home/amecioni/Documents/projects/test.

~/Documents/projects/test
reana ❯ unzip download_2021-04-20-081952.zip
Archive:  download_2021-04-20-081952.zip
  inflating: code/gendata.C
  inflating: code/fitdata.C

~/Documents/projects/test
reana ❯ l
drwxrwxr-x    - amecioni 2021-04-20 10:20  code
.rw-rw-r-- 1.8k amecioni 2021-04-20 10:19  download_2021-04-20-081952.zip

~/Documents/projects/test
reana ❯ l code
.rw-rw-r-- 1.6k amecioni 2021-04-19 14:27  fitdata.C
.rw-rw-r-- 1.9k amecioni 2021-04-19 14:27  gendata.C