feat: add a column containing image digest in generated reports for containers (UI)

[xingzhang-suse]

Is your feature request related to a problem? Please describe.

A container image tag is mutable information,

Describe the solution you'd like

In order to clearly identify compromised images we also need to know the image digest.

Describe alternatives you've considered
/

Additional context
Add any other context or screenshots about the feature request here.

image_name	tags	digest	workload_name	namespace	host_name	CVE name	link	severity	score	score_v3	package_name	package_version	fixed_version	description	feed_rating	file_name	vectors	vectors_v3	in_base_image	published_timestamp	last_modified_timestamp
quay.io/calico/apiserver	v3.31.3	insert image digest here	k8s_calico-apiserver_calico-apiserver-b9ddbd7b6-vt7qj_calico-system_d925ced4-19ef-4336-934e-6d2f3a8d4ace_0	calico-system	K8-Master	CVE-2024-7598	kubernetes/kubernetes#126587	Low	1	3.1	go:k8s.io/kubernetes	1.33.6		Network restriction bypass via race condition during namespace termination	Low	code/apiserver		CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N		Jan 20 1970 20:01:30	Jan 20 1970 20:01:45
quay.io/calico/apiserver	v3.31.3	insert image digest here	k8s_calico-apiserver_calico-apiserver-b9ddbd7b6-vt7qj_calico-system_d925ced4-19ef-4336-934e-6d2f3a8d4ace_0	calico-system	K8-Master	CVE-2025-61726	http://people.ubuntu.com/~ubuntu-security/cve/CVE-2025-61726	High	7	7.5	go:stdlib	1.24.11	>=1.24.12;>=1.25.6	The net/url package does not set a limit on the number of query parameters in a query.While the maximum size of query parameters in URLs is generally limited by the maximum request header size, the net/http.Request.ParseForm method can parse large URL-encoded forms. Parsing a large form containing many unique query parameters can cause excessive memory consumption.	High	code/apiserver		CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H		Jan 21 1970 03:33:51	Jan 21 1970 03:46:43

[williamlin-suse]

For POST(/v1/scan/workloads/scan_report), the response payload will include a new field workload_image_digest (array type).

Example:

Please notice usually the new field workload_image_digest contains one entry only.
However, on docker runtime env it's possible that there are multiple images found for an image id & enforcer cannot really tell which one is used by the workload. In this case all the image digests are added in the new field workload_image_digest.