Add logo to carvel packages

Essentially we need to add `iconSVGBase64` into `PackageMetadata` which is base64 encoded svg logo.

For example:
https://github.com/vmware-tanzu/community-edition/blob/b354f80c4909d7e63f767c03039d48f91990745d/addons/packages/cert-manager/metadata.yaml#L9

Logos are currently only used in UI products like Tanzu Mission Control UI for Catalogue services.