[FEATURE] PDCP Login on first run

[olearycrew]

Describe your feature request

Implement a feature in Nuclei that prompts the user to log in to the ProjectDiscovery Cloud Platform (PDCP) on the first run if no existing credentials are found. The prompt should offer multiple login options (e.g., GitHub, GitLab, Bitbucket, Email, SAML Single Sign-On) and provide an option to skip the login process.

Describe the use case of the feature

This feature aims to streamline the user experience by integrating Nuclei with PDCP authentication from the first use. By prompting users to log in on the initial run, we can ensure they are authenticated and can benefit from centralized authentication across all ProjectDiscovery tools. This will enhance security, provide a seamless user experience, and allow users to access PDCP features and services immediately.

Describe alternatives you've considered

No response

Additional context

The login prompt should be similar to the Vercel CLI, offering a clear and user-friendly interface.

Example prompt:

root@vultr:~# nuclei
Nuclei CLI [Version]
> No existing credentials found. Please log in:
? Log in to ProjectDiscovery Cloud Platform (Use arrow keys)
❯ Continue with GitHub
  Continue with Email
  Continue with SAML Single Sign-On
─────────────────────────────────
  Skip Login

• Users should be able to choose to skip the login process if they prefer not to authenticate with PDCP at that time.
• Ensure that the implementation is secure and that user credentials are handled appropriately.

[olearycrew]

More examples from the Vercel CLI:

We could also consider examples from https://charm.sh/ as inspiration