rpm2img: add support for aliases for packages

[piyush-jena]

Description of changes:
This PR allows creation of aliases for packages whose name is changed so as to support multiple versions of the same package. For example: bottlerocket-core-kit supports containerd-1.7, containerd-2.0 and containerd-2.1. With this change, we allow creation of aliases so that we get additional entries in the application-inventory.json which can ensure that compliance solutions are able to properly track the old packages with new names.

Testing done:
These changes may or may not be valid for the actual repo but attempts to test corner cases.
I added the following Obsoletes in containerd-2.0

Obsoletes: %{_cross_os}%{gorepo}
Obsoletes: %{_cross_os}%{gorepo}-1.7
Obsoletes: %{_cross_os}%{gorepo} <= 1.7.15

This the output I got after making the above change for containerd-2.0, building the package and mounting the rpm in a bottlerocket-sdk container.

bash-5.2$ rpm -qp --queryformat '[%{OBSOLETES}\n]' /containerd-2.0/bottlerocket-containerd-2.0-2.0.7-1.1764962845.9b3a8b3a.br1.x86_64.rpm
bottlerocket-containerd
bottlerocket-containerd
bottlerocket-containerd-1.7

I used the above to write the logic. I added Obsoletes for systemd-252 as well.

Additional entries in application-inventory.json

   {
      "Name": "containerd",
      "Publisher": "Bottlerocket",
      "Version": "2.0.7",
      "Release": "1.1764962845.9b3a8b3a.br1",
      "Epoch": "1",
      "InstalledTime": "2025-12-18T19:28:28Z",
      "ApplicationType": "Unspecified",
      "Architecture": "x86_64",
      "Url": "https://github.com/containerd/containerd",
      "Summary": "An industry-standard container runtime"
    },
    {
      "Name": "containerd-1.7",
      "Publisher": "Bottlerocket",
      "Version": "2.0.7",
      "Release": "1.1764962845.9b3a8b3a.br1",
      "Epoch": "1",
      "InstalledTime": "2025-12-18T19:28:28Z",
      "ApplicationType": "Unspecified",
      "Architecture": "x86_64",
      "Url": "https://github.com/containerd/containerd",
      "Summary": "An industry-standard container runtime"
    },
    {
      "Name": "systemd",
      "Publisher": "Bottlerocket",
      "Version": "252.39",
      "Release": "1.1764962845.9b3a8b3a.br1",
      "Epoch": "0",
      "InstalledTime": "2025-12-18T19:28:28Z",
      "ApplicationType": "Unspecified",
      "Architecture": "x86_64",
      "Url": "https://www.freedesktop.org/wiki/Software/systemd",
      "Summary": "System and Service Manager"
    }

containerd-2.0

Obsoletes: %{_cross_os}%{gorepo}
Obsoletes: %{_cross_os}%{gorepo}-1.7
Obsoletes: %{_cross_os}%{gorepo} <= 1.7.15

systemd-252

Obsoletes: %{_cross_os}systemd

Terms of contribution:

By submitting this pull request, I agree that this contribution is dual-licensed under the terms of both the Apache License, version 2.0, and the MIT license.

[piyush-jena]

Updated the logic to accomodate the above comments. Testing corner cases are detailed in the description above.