Standardize user identification flags across CLI commands - fix for #2631

[tevinflores]

This PR replaces inconsistent -u/--user arguments with the standard --identifier/--name flags for user identification. Previously, some commands used --user to accept either a user ID (uint) or username (string), creating confusion and inconsistent behavior. This change provides a more explicit and predictable interface for specifying users throughout the CLI.

• [x] have read the CONTRIBUTING.md file
• [x] raised a GitHub issue or discussed it on the projects chat beforehand
• [x] added unit tests
• [x] added integration tests
• [ ] updated documentation if #needed
• [ ] updated CHANGELOG.md

Issue ref: #2631

[ghost]

Pull Request Revisions

Revision	Description
r2	CLI flags renamed and refactored Renamed CLI flags across multiple commands, changing from --name to --user and --identifier to --node-id, with associated logic updates
r1	Refactored CLI user identification flags Introduced a new helper function findSingleUser and standardized user identification flags across multiple CLI commands, replacing deprecated namespace flags with consistent username and ID flags.

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☑️ AI review skipped for r2

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