feat(report): export modified findings in JSON

[knqyf263]

Description

--show-suppressed exports modified findings in JSON.

Before

$ cat .trivyignore
CVE-2022-0563
$ trivy image -q -f json --show-suppressed debian:11 | jq ".Results[].ExperimentalModifiedFindings | length" 
0

After

$ cat .trivyignore
CVE-2022-0563
$ trivy image -q -f json --show-suppressed debian:11 | jq ".Results[].ExperimentalModifiedFindings | length" 
7

Related issues

• Close Enable --show-suppressed in JSON format #7382

Checklist

• I've read the guidelines for contributing to this repository.
• I've followed the conventions in the PR title.
• I've added tests that prove my fix is effective or that my feature works.
• I've updated the documentation with the relevant information (if needed).
• I've added usage information (if the PR introduces new options)
• I've included a "before" and "after" example to the description (if the PR is a user interface change).

[DmitriyLewen]

LGTM