Removed some code smells

[Rachit1606]

Hi, I am a masters student at dal and as a project I picked up your repo and refactored some code smells which occurred please check the changes and according accept or reject the pull request. you code is working its just i refactored some code.

Category (place an x in each of the [ ])

• [ ] bolt (Bolt for Java)
• [ ] bolt-{sub modules} (Bolt for Java - optional modules)
• [ ] slack-api-client (Slack API Clients)
• [ ] slack-api-model (Slack API Data Models)
• [ ] *slack-api--kotlin-extension** (Kotlin Extensions for Slack API Clients)
• [x] slack-app-backend (The primitive layer of Bolt for Java)

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[salesforce-cla[bot]]

Thanks for the contribution! Unfortunately we can't verify the commit author(s): rachit r***@d***.ca. One possible solution is to add that email to your GitHub account. Alternatively you can change your commits to another email and force push the change. After getting your commits associated with your GitHub account, sign the Salesforce Inc. Contributor License Agreement and this Pull Request will be revalidated.

[seratch]

Hi @Rachit1606, thanks for sending this PR! However, moving DialogSubmissionPayload.Team etc. to the top level package can be a breaking change for existing users (please note that this SDK is used by many Slack customers for their business operations), so we are unable to accept such changes.

If you're still interested in improving this project, I'd suggest making changes that do not bring any public interface modifications such as runtime performance / memory usage improvements.

Let me close this PR for the above reason. Thanks again for your interest!