- Replaced all instances of subprocess.check_output with subprocess_check_output
- Added subprocess_check_output function to handle current repo directory
- Updated git commands to use the new subprocess_check_output function
- Renamed `read_config` to `read_config_item` and updated its usage
- Renamed `save_config` to `save_config_item` and updated its usage
- Renamed `save_branch` parameter to `base_branch` in `save_last_base_branch`
- Introduce functions to read and save last base branch from config
- Modify PR creation and update commands to use dynamic base branch
- Enable user interaction to edit base branch during PR operations
