Added `time` import in the eml_test.go and added two new test use-cases: `exampleMailPlainNoEncInvalidDate` and `exampleMailPlainNoEncNoDate`. The `exampleMailPlainNoEncInvalidDate` is used to check if the parser can correctly handle email with invalid date. Meanwhile, `exampleMailPlainNoEncNoDate` checks if the parser can correctly add the current date to an email that didn't specify a date. This will improve the parser's resilience and flexibility in handling various email scenarios.
The test emails in the eml_test.go file have been updated with more diverse fields, including variations of encoding types. These changes help improve the robustness of our parser tests by evaluating its function with a wider range of email structures. Tests including quoted-printable and base64 encoded emails have been added.
A new test `TestEMLToMsgFromString` was added to "eml_test.go". This test asserts the proper functionality of `EMLToMsgFromString` method that allows us to parse EMLs directly from a string input. This test is a necessary part of ensuring the functionality and reliability of our EML parsing process.
