image-info: show format version for qcow2

Change the "image-format" from a string to a dict, with a "type":
$value entry, where $value contains the previous plain string
data.
Additionally, include the qcow2 format version, if the given
image is indeed a qcow2.
Adapt all manifest test accordingly (partly done by Ondřej)

Python 3 script used for conversion of manifest tests:
import os
import json

for name in os.listdir(os.getcwd()):
    if not name.endswith(".json"):
        continue
    print(name)
    with open(name, "r") as old:
        data = json.load(old)
        info = data.get("image-info", {})
        format = info.get("image-format")
        if not format:
            continue
        info["image-format"] = {
            "type": format
        }
        if format != "qcow2":
            continue
        info["image-format"]["compat"] = "1.1"
        with open(name + ".new", "w") as new:
            json.dump(data, new, indent=2)
            new.write("\n")
            new.flush()
    os.rename(name+".new", name)

test: use the new image-info format in all test manifests

The previous commit converted only qcow2 and openstack manifests but this change
is actually needed for all manifests produced by the qemu assembler.

Co-Developed-by: Ondřej Budai <ondrej@budai.cz>

test/data/manifests/rhel_8-x86_64-openstack-boot.json

@@ -9141,7 +9141,10 @@
       "video:x:39:",
       "wheel:x:10:"
     ],
-    "image-format": "qcow2",
+    "image-format": {
+      "type": "qcow2",
+      "compat": "1.1"
+    },
     "os-release": {
       "ANSI_COLOR": "0;31",
       "BUG_REPORT_URL": "https://bugzilla.redhat.com/",