Keep info about output files within sandbox

[mtitov]

related to #3276
in src/radical/pilot/agent/executing/base.py

L288: https://github.com/radical-cybertools/radical.pilot/pull/3276/files#diff-f16b90015a62a91010ce901f4d97c31e25fc9c338945e13f82574013597cb6f7R288

L300: https://github.com/radical-cybertools/radical.pilot/pull/3276/files#diff-f16b90015a62a91010ce901f4d97c31e25fc9c338945e13f82574013597cb6f7R300

need to provide $RP_TASK_SANDBOX for .files and .ofiles files

from use case: pre-exec changes working directory and then that files appear there

[andre-merzky]

The docstring specifically states:

        Warning:
            This can be incomplete: the heuristics will not detect files which
            start with `<task_id>.`, for example.  It will also not detect files
            which are not created in the task sandbox.

I would like to avoid this outside of the task sandbox: there is no telling if the task created the file, or if some other process or user did so. That is opening too many cans of wurms for my liking...

[mtitov]

I mostly was about keeping RP related files within corresponding sandboxes, e.g., ... > $RP_TASK_SANDBOX/task.000000.files, otherwise this file (and .ofiles) appears outside of task sandbox

[andre-merzky]

Ah, sorry, I misunderstood that. Thanks for clarifying!