feat(scripts): assign spec-compliant Margo media types to application package resource files

[sanjujunnuthula]

This PR updates the OCI packaging script (scripts/modules/packages.sh) to adhere to the Margo Application Registry Specification when pushing application package resource files.

Previously, all resource files inside resources/ were pushed as generic application/octet-stream layers. This update inspects margo.yaml (and falls back to file name conventions) to assign the appropriate Margo-specific media type and format suffix to each layer.

Key Changes

1. Added get_margo_media_type Helper:
   • Matches referenced files under metadata.catalog.application in margo.yaml (icon, descriptionFile, releaseNotes, licenseFile).
   • Maps file extensions (.md, .png, .jpg, .txt, .pdf, etc.) to the required format suffixes (+markdown, +png, +jpeg, +plain, +pdf).
   • Dynamically constructs the layer media types:
     • application/vnd.margo.app.icon.v1+{format}
     • application/vnd.margo.app.descriptionFile.v1+{format}
     • application/vnd.margo.app.releaseNotes.v1+{format}
     • application/vnd.margo.app.licenseFile.v1+{format}
2. Updated Package Push Functions:
   • Replaced hardcoded application/octet-stream in push_nextcloud_to_oci and push_custom_otel_to_oci with dynamic media type resolution.

[spulkit138]

Looks Good! Can be merged if tested.