feat: DTOSS-8078-Update GetValidationExceptions tests

[Swapnil261188]

Description

Updated and improved automated tests to include Component tests (Happy and Unhappy paths) and unit tests for GetValidationExceptions .
Current coverage is 100%

PFB the jira ticket link:
https://nhsd-jira.digital.nhs.uk/browse/DTOSS-8078

Context

Type of changes

• Refactoring (non-breaking change)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would change existing functionality)
• Bug fix (non-breaking change which fixes an issue)

Checklist

• I am familiar with the contributing guidelines
• I have followed the code style of the project
• I have added tests to cover my changes
• I have updated the documentation accordingly
• This PR is a result of pair or mob programming

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