Generating a report after the execution of workflow.

[BoPeng]

Many workflow systems (e.g. nextflow and snakemake) generates a report after the completion of a workflow, including all the information such as steps executed, CPU/MEM usages, time, perhaps information on intermediate files. It is nice to have because it keeps all information in one place and users can refer back to the report if needed. SoS already has most of the information at hand and it would be nice to offer an option to create a report.

Hard to get name for an option though because we are limited to single letter options for sos run. -r is already used by remote execution.

[BoPeng]

@gaow I am still working on this ticket but the framework is done and ready for comment. More specifically,

1. report.py is added to collect workflow runtime information during execution. Right now it only collects these.
2. A jinja2 templste is added to show the information.

Right now the template is very crude and I am adding CSS, but more importantly we need to decide what to display in the report. I am thinking of

1. start/end/duration of tasks.
2. tags for tasks because they relate tasks to step/ID etc
3. CPU/MEM usage of tasks because they are available.

I am not sure if it is needed to list the executed steps, input and output files etc.

This feature re-uses the reporting mechanism used for pack/unpack but is no longer compatible with them. pack/unpack are therefore removed, at least for now.

[BoPeng]

Roughly done.