Add possibility to provide a filepath to the --summary-file option in the publish command

Description

This PR introduces a new capability to the Lerna library, allowing users to specify a filepath instead of a directory path for the --summary-file option.

Previously, users could only provide a directory path and the created filename is statically defined in the code as lerna-publish-summary.json , which limited the flexibility in defining the location and name of the summary file.

Motivation and Context

With this change, users can now directly specify the full path, including the filename, where the summary should be saved.

How Has This Been Tested?

In the publish-command.spec.ts file, adding a new test case where a filepath is passed as input parameter.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Chore (change that has absolutely no effect on users)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.