Refactor execute_snakemake function to dynamically generate snakemake_cmd based on configuration settings.

[druvus]

Changes made:

• Modify execute_snakemake to accept a config_contents parameter, which contains 'conda_frontend' and 'local_package_management' settings.
• Dynamically build snakemake_cmd based on 'local_package_management' setting:
  • If 'local_package_management' is 'conda', include '--use-conda' and '--conda-frontend' options in snakemake_cmd.
  • If 'local_package_management' is 'None', exclude conda-related options in snakemake_cmd.
• Improve code readability and maintainability.

These changes allow for more flexibility in handling package management settings when executing Snakemake workflows.