fix: report.json doesn't include details of parsing failures

[cka-y]

Summary:
When the stderr displays this error message:

SEVERE:  ----------------------------------------- 
|       !!!    PARSING FAILED    !!!      |
|   Some validators were never invoked.   |
|   Please see report.json for details.   |
 ----------------------------------------- 

the report.json file doesn't include anything related to the parsing failure.

Expected behavior:
Closes #1193

Since parsing failure specific notices are present in the validation reports (html & json), we removed all confusing logs related to parsing failures as shown bellow.

SEVERE: 
 ----------------------------------------- 
|   Some validators were never invoked.   |
 ----------------------------------------- 
Skipped validators: FareAttributeAgencyIdValidator,GtfsAttributionAgencyIdForeignKeyValidator,GtfsAttributionRouteIdForeignKeyValidator,GtfsFareAttributeAgencyIdForeignKeyValidator,GtfsFareLegRuleNetworkIdForeignKeyValidator,GtfsFareRuleRouteIdForeignKeyValidator,GtfsRouteAgencyIdForeignKeyValidator,GtfsTransferFromRouteIdForeignKeyValidator,GtfsTransferToRouteIdForeignKeyValidator,GtfsTripRouteIdForeignKeyValidator,MatchingFeedAndAgencyLangValidator,RouteAgencyIdValidator,ShapeToStopMatchingValidator,StopTimeTravelSpeedValidator,TranslationFieldAndReferenceValidator,UrlConsistencyValidator

In the case of poa.zip dataset, the notice related to the parsing failure is invalid_color.

Also, MISSING_FILE log for optional files has been removed as requested in #1193

Please make sure these boxes are checked before submitting your pull request - thanks!

• Run the unit tests with gradle test to make sure you didn't break anything
• Format the title like "feat: [new feature short description]". Title must follow the Conventional Commit Specification(https://www.conventionalcommits.org/en/v1.0.0/).
• Linked all relevant issues
• Include screenshot(s) showing how this pull request works and fixes the issue(s)

[github-actions]

✅ Rule acceptance tests passed.
New Errors: 0 out of 1435 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
Dropped Errors: 0 out of 1435 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
New Warnings: 0 out of 1435 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
Dropped Warnings: 0 out of 1435 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
0 out of 1435 sources (~0 %) are corrupted.
Commit: 77fdb2e
Download the full acceptance test report here (report will disappear after 90 days).
✅ Rule acceptance tests passed.

[github-actions]

✅ Rule acceptance tests passed.
New Errors: 0 out of 1435 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
Dropped Errors: 0 out of 1435 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
New Warnings: 0 out of 1435 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
Dropped Warnings: 0 out of 1435 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
0 out of 1435 sources (~0 %) are corrupted.
Commit: db792a1
Download the full acceptance test report here (report will disappear after 90 days).
✅ Rule acceptance tests passed.

[github-actions]

✅ Rule acceptance tests passed.
New Errors: 0 out of 1435 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
Dropped Errors: 0 out of 1435 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
New Warnings: 0 out of 1435 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
Dropped Warnings: 0 out of 1435 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
0 out of 1435 sources (~0 %) are corrupted.
Commit: c11d189
Download the full acceptance test report here (report will disappear after 90 days).
✅ Rule acceptance tests passed.

[qcdyx]

LGTM