cve-check: add json format

Backport to dunfell from master df567de36ae5964bee433ebb97e8bf702034994a

Add an option to output the CVE check in a JSON-based format.
This format is easier to parse in software than the original
text-based one and allows post-processing by other tools.

Output formats are now handed by CVE_CHECK_FORMAT_TEXT and
CVE_CHECK_FORMAT_JSON. The text format is enabled by default
to maintain compatibility, while the JSON format is disabled
by default.

The JSON output format gets generated in a similar way to the
text format with the exception of the manifest: appending to
JSON arrays requires parsing the file. Because of that we
first write JSON fragments and then assemble them in one pass
at the end.

(From OE-Core rev: 92b6011ab25fd36e2f8900a4db6883cdebc3cd3d)

Signed-off-by: Marta Rybczynska <marta.rybczynska@huawei.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/lib/oe/cve_check.py

@@ -63,3 +63,19 @@ def _cmpkey(release, patch_l, pre_l, pre_v):
     else:
         _pre = float(pre_v) if pre_v else float('-inf')
     return _release, _patch, _pre
+
+def cve_check_merge_jsons(output, data):
+    """
+    Merge the data in the "package" property to the main data file
+    output
+    """
+    if output["version"] != data["version"]:
+        bb.error("Version mismatch when merging JSON outputs")
+        return
+
+    for product in output["package"]:
+        if product["name"] == data["package"][0]["name"]:
+            bb.error("Error adding the same package twice")
+            return
+
+    output["package"].append(data["package"][0])