[Suggestion] Metadata and json output in distrobox v2

**Is your feature request related to a problem? Please describe.**
Hello, I'm the developer of DistroShelf, a gtk4 GUI for distrobox. I've just seen you guys are planning on doing a v2 rewrite. Could you add some metadata in the v2 version, so that external programs can more easily interface with distrobox?

**Describe the solution you'd like**
Podman (and I guess docker as well) supports the `--format json` argument for most commands. That provides the output as json. An external program such as DistroShelf could use that to interface with distrobox.

Also, a "v2" version metadata in the exported .desktop files would be helpful, so that external programs can list the exported files from distrobox v1, see that the version is different, and prompt the user to upgrade the old .desktop exports.

**Additional context**
distrobox is great! Thanks for building it. Being able to run programs from any distro is kind of magic

查看程式碼庫中的 distrobox 指令實作，可能位於 cmd/ 或類似目錄下，以了解目前如何格式化輸出。調查 podman/docker 如何為其指令實作 --format json。對於 .desktop 檔案的版本中繼資料，找出產生和匯出 .desktop 檔案的位置。新增 JSON 輸出將涉及修改多個指令處理程式，以支援結構化格式。透過使用新的 --format json 旗標執行 distrobox 指令，並確認輸出是有效的 JSON，來測試變更。

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