feat: enhance JSON output for multi-profile validation

[kikkomep]

This PR refines the JSON output generated by validating a rocrate that requires multiple profiles, not belonging to the same inheritance hierarchy.

The main changes are as follows:

• the output will be a single JSON object, unlike before when a separate JSON was produced for each validation profile used
• the profile_identifier property is replaced by profile_identifiers, which will be populated with the list of validation profiles used
• the issues property will contain the list of all issues encountered during the crate validation across the various involved validation profiles

[simleo]

I tried the following and got an error:

$ rocrate-validator -y validate -v -f json -o err.json -l REQUIRED tests/data/crates/valid/multi-profile-crate/
         This error may be due to a bug.
         Please report it to the issue tracker along with the following stack trace:

╭─────────────────────────────── Traceback (most recent call last) ────────────────────────────────╮
│ /home/simleo/git/rocrate-validator/rocrate_validator/cli/commands/validate.py:439 in validate    │
│                                                                                                  │
│   436 │   │   │   # Print the validation report to a file                                        │
│   437 │   │   │   if output_file:                                                                │
│   438 │   │   │   │   with open(output_file, "w") as f:                                          │
│ ❱ 439 │   │   │   │   │   f.write(json_output)                                                   │
│   440 │   │                                                                                      │
│   441 │   │   # using ctx.exit seems to raise an Exception that gets caught below,               │
│   442 │   │   # so we use sys.exit instead.                                                      │
╰──────────────────────────────────────────────────────────────────────────────────────────────────╯
TypeError: write() argument must be str, not dict


[ERROR] 

[FAILED] Unexpected error: write() argument must be str, not dict !!!

BTW, tests/data/crates/valid/multi-profile-crate does not seem to be valid with respect to https://w3id.org/ro/wftest/0.1, there is no test suite.

[simleo]

I ran:

rocrate-validator -y validate -v -f json -o err.json -l REQUIRED tests/data/crates/invalid/0_multi_profile_crate/

and got the attached err.json. profile_identifiers lists both workflow-testing-ro-crate-0.1 and provenance-run-crate-0.5, but no validation seems to have been performed with respect to workflow-testing-ro-crate-0.1: the fact that the root data entity does not refer to test suites via mentions (a MUST) is not reported.

Another weird thing is that if I set -p workflow-testing-ro-crate I only get issues if the output is in text format, while with JSON output I get this:

{
    "meta": {
        "version": "0.2"
    },
    "validation_settings": {
        "profile_identifier": "workflow-testing-ro-crate-0.1",
        "enable_profile_inheritance": true,
        "abort_on_first": false,
        "requirement_severity": "REQUIRED",
        "rocrate_validator_version": "0.6.1_bd0cc32+448-dirty"
    },
    "passed": false,
    "issues": []
}