Add --json output to advisory info

[stewartsmith]

Enable --json for 'dnf advisory info'. The same information as would be displayed as text is included in the JSON output. While the libscols code could be adapted to produce JSON as well, without serious reworking of key_value_table (and all callers), the produced JSON is quite weird, so we instead choose to implement the JSON output separately.

Example output from dnf5 advisory info --json FEDORA-2024-1ec4cd5fd3:

{
  "FEDORA-2024-1ec4cd5fd3":{
    "Name":"FEDORA-2024-1ec4cd5fd3",
    "Title":"libtirpc-1.3.6-1.fc41",
    "Severity":"None",
    "Type":"unspecified",
    "Status":"stable",
    "Vendor":"[email protected]",
    "Issued":"2024-11-16 02:13:46",
    "Description":"    - Fix regression in NVR\n    - Removed libtirpc-1-3-7-rc1 patch (bz 2325556)\n",
    "Message":"",
    "Rights":"Copyright (C) 2024 Red Hat, Inc. and others.",
    "references":[
      {
        "Title":"[nfs-utils] nfs-server restart times out",
        "Id":"2325556",
        "Type":"bugzilla",
        "Url":"https:\/\/bugzilla.redhat.com\/show_bug.cgi?id=2325556"
      }
    ],
    "collections":{
      "packages":[
        "libtirpc-1.3.6-1.fc41.src",
        "libtirpc-debuginfo-1.3.6-1.fc41.i686",
        "libtirpc-1.3.6-1.fc41.i686",
        "libtirpc-debugsource-1.3.6-1.fc41.i686",
        "libtirpc-devel-1.3.6-1.fc41.i686",
        "libtirpc-debuginfo-1.3.6-1.fc41.x86_64",
        "libtirpc-1.3.6-1.fc41.x86_64",
        "libtirpc-devel-1.3.6-1.fc41.x86_64",
        "libtirpc-debugsource-1.3.6-1.fc41.x86_64",
        "libtirpc-debuginfo-1.3.6-1.fc41.aarch64",
        "libtirpc-debugsource-1.3.6-1.fc41.aarch64",
        "libtirpc-devel-1.3.6-1.fc41.aarch64",
        "libtirpc-1.3.6-1.fc41.aarch64",
        "libtirpc-1.3.6-1.fc41.ppc64le",
        "libtirpc-debuginfo-1.3.6-1.fc41.ppc64le",
        "libtirpc-debugsource-1.3.6-1.fc41.ppc64le",
        "libtirpc-devel-1.3.6-1.fc41.ppc64le",
        "libtirpc-devel-1.3.6-1.fc41.s390x",
        "libtirpc-debuginfo-1.3.6-1.fc41.s390x",
        "libtirpc-debugsource-1.3.6-1.fc41.s390x",
        "libtirpc-1.3.6-1.fc41.s390x"
      ]
    }
  }
}

[kontura]

I have only a couple really minor simplification notes.

Otherwise this looks good.
Thank you!

[kontura]

Great, thank you again!