#8 Test classes, add Codecov workflow

[JavaCoDED78]

PR-Codex

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PR-Codex overview

This PR updates the Java library for JWT tokens with improved testing, updated dependencies, and added Codecov integration.

Detailed summary

• Added Codecov integration to the project
• Updated JUnit and Jacoco versions in the pom.xml
• Improved testing in TokenParametersTest and TokenServiceImplTest
• Refactored method signatures in TokenService and TokenServiceImpl

The following files were skipped due to too many changes: src/main/java/io/github/javacoded78/jwthumble/TokenParameters.java

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[codecov-commenter]

Welcome to Codecov 🎉

Once you merge this PR into your default branch, you're all set! Codecov will compare coverage reports and display results in all future pull requests.

ℹ️ You can also turn on project coverage checks and project coverage reporting on Pull Request comment

Thanks for integrating Codecov - We've got you covered ☂️