[FEATURE REQUEST] Epicli prepare - generate files in separate directory

[rafzei]

Is your feature request related to a problem? Please describe.
epicli prepare overwriting target directory

Describe the solution you'd like
It should generate os-specific directory name eg.:

• prepare_script_centos7
• prepare_script_rhel7
• prepare_script_ubuntu18

Describe alternatives you've considered
Add a new optional argument to specify target directory.
eg.
epicli prepare --os centos-7 --output_dir scripts_centos7
epicli prepare --os centos-7 -o scripts_centos7

Additional context
None

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DoD checklist

• Changelog updated
• COMPONENTS.md updated / doesn't need to be updated
• Schema updated / doesn't need to be updated
• Feature has automated tests
• Automated tests passed (QA pipelines)
  • apply
  • upgrade
• Idempotency tested
• Documentation added / updated / doesn't need to be updated
• All conversations in PR resolved
• Solution meets requirements and is done according to design doc
• Usage compliant with license
• Backport tasks created / doesn't need to be backported