Add command: Invalid birthday is acepted without error

[nus-se-script]

steps to recreate: add n/shark p/999 e/local-part@domain a/ocean u/NTU m/IS b/31-02-2000 expected: date of 31-02-2000 should not be accepted and error should be raised to user actual: date is automatically changed to 29-02-2000 without informing user

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_{[original: nus-cs2103-AY2425S1/pe-interim#3010] [original labels: severity.Low type.FunctionalityBug]}

[verakohh]

Team's Response

We will include an error message that the date does not exist

Duplicate status (if any):

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