Add GitHub Container Registry Support to Portal UI

[SergK]

Is your feature request related to a problem? Please describe. Currently, the Portal UI supports interactions primarily with dockerhub.io for container registries. This feature request aims to extend the support to include GitHub Container Registry (GHCR), ensuring a wider range of registry options for users.

Describe the solution you'd like The Portal UI should be enhanced to include support for GHCR, allowing for seamless interaction and functionality similar to what is currently available for dockerhub.io. This includes:

1. Aligning UI components and elements for GHCR.
2. Utilizing the https://ghcr.io endpoint for creating secrets related to container registries.
3. Ensuring compatibility and functionality with GHCR through proper validation and testing.
4. Updating documentation with guidelines for using GHCR with the Portal UI.

Describe alternatives you've considered N/A

Additional context This feature aims to provide users with more options for container registries and enhance the usability of the Portal UI by incorporating support for GHCR, following an evaluation of the current UI components related to dockerhub.io integration and the specific requirements of ghcr.io.

[Serg1506]