[graph] Changed graph info json output

[franramirez688]

Changelog: Bugfix: Fixed and completed the graph info xxxx --format json output, to publicly document it.
Docs: conan-io/docs#3236

Closes: #13911
Closes: #13862

For instance:

{
    "nodes": {
         "0": {
            "ref": "pkga/0.1",
            "id": 0,
            "recipe": "Consumer",
            "package_id": "041db7e16de982fbd01f61f3809fc1c206fa9931",
            "prev": null,
            "build_id": null,
            "binary": null,
            "invalid_build": false,
            "info_invalid": null,
            "name": "pkga",
            "user": null,
            "channel": null,
            "url": null,
            "license": null,
            "author": null,
            "description": null,
            "homepage": null,
            "build_policy": null,
            "upload_policy": null,
            "revision_mode": "hash",
            "provides": null,
            "deprecated": null,
            "win_bash": null,
            "win_bash_run": null,
            "default_options": null,
            "options_description": null,
            "version": "0.1",
            "topics": null,
            "package_type": "unknown",
            "settings": {},
            "options": {},
            "options_definitions": {},
            "generators": [],
            "system_requires": {},
            "recipe_folder": "/private/var/folders/s8/zgn806y90xq7bdh64hhfw9th0000gr/T/tmpze4f_1t9conans/path with spaces",
            "source_folder": null,
            "build_folder": null,
            "generators_folder": null,
            "package_folder": null,
            "cpp_info": {
                "root": {
                    "includedirs": [
                        "include"
                    ],
                    "srcdirs": null,
                    "libdirs": [
                        "lib"
                    ],
                    "resdirs": null,
                    "bindirs": [
                        "bin"
                    ],
                    "builddirs": null,
                    "frameworkdirs": null,
                    "system_libs": null,
                    "frameworks": null,
                    "libs": null,
                    "defines": null,
                    "cflags": null,
                    "cxxflags": null,
                    "sharedlinkflags": null,
                    "exelinkflags": null,
                    "objects": null,
                    "sysroot": null,
                    "requires": null,
                    "properties": null
                }
            },
            "label": "conanfile.py (pkga/0.1)",
            "dependencies": {
                "1": {
                    "ref": "pkgb/0.1@common/unstable",
                    "run": "False",
                    "libs": "True",
                    "skip": "False",
                    "test": "False",
                    "force": "False",
                    "direct": "True",
                    "build": "False",
                    "transitive_headers": "None",
                    "transitive_libs": "None",
                    "headers": "True",
                    "package_id_mode": "semver_mode",
                    "visible": "True"
                },
                "3": {
                    "ref": "ros_perception/1.1.4@3rdparty/unstable",
                    "run": "False",
                    "libs": "True",
                    "skip": "False",
                    "test": "False",
                    "force": "False",
                    "direct": "True",
                    "build": "False",
                    "transitive_headers": "None",
                    "transitive_libs": "None",
                    "headers": "True",
                    "package_id_mode": "semver_mode",
                    "visible": "True"
                },
                "2": {
                    "ref": "ros_core/pr-53@3rdparty/snapshot",
                    "run": "False",
                    "libs": "True",
                    "skip": "False",
                    "test": "False",
                    "force": "True",
                    "direct": "True",
                    "build": "False",
                    "transitive_headers": "None",
                    "transitive_libs": "None",
                    "headers": "True",
                    "package_id_mode": "semver_mode",
                    "visible": "True"
                }
            },
            "context": "host",
            "test": false
    },

    [....],

     "root": {
        "0": "pkga/0.1"
    },
    "overrides": {
        "ros_core/[~1.1]@3rdparty/unstable": [
            "ros_core/pr-53@3rdparty/snapshot"
        ],
        "ros_core/1.1.4@3rdparty/unstable": [
            "ros_core/pr-53@3rdparty/snapshot#4d670581ccb765839f2239cc8dff8fbd"
        ]
    },
    "resolved-ranges": {
        "pkgb/[~0]@common/unstable": "pkgb/0.1@common/unstable",
        "ros_perception/[~1.1]@3rdparty/unstable": "ros_perception/1.1.4@3rdparty/unstable"
    }
}

[memsharded]

Looks good, just a minor comment