modified to capture stdout and stderr to log in using system2() being…

[kjsato]

… applicable in Windows as well in flepimop/main_scripts/inference_main.R

Describe your changes.

• use system2() in place of system(), with dir precheck to capture msgs on both stdout and stdout
• modified (assumed) to run in Windows as well
  • Checked okay on WSL2-Windows(ubuntu) of course
• use 'tryCatch'

What does your pull request address? Tag relevant issues. https://github.com/HopkinsIDD/flepiMoP/issues/169 Mentions of relevant team members. Please check out whether it works if possible @kimberlynroosa @saraloo

[kjsato]

sorry, I set appropriate persons for reviewers (note that the priority is low) @kimberlynroosa plz check on MINGW64 environment which you seemed to use