More complete way of adding typings for the Server module

[jmordica]

• Conformed to the way typings are being added currently in the project
• Fixed an issue importing PrepareStatementInfo (while we're at it)

[sidorares]

not sure why https://github.com/sidorares/node-mysql2/actions/workflows/code-coverage.yml is still failing, I disabled in manually

Could you add some typings unit tests for types covered in this pr? ( And perhaps ones discussed in #1584 (comment) )

[jmordica]

Looks like checks are failing because the package-lock.json isn't synced with the package.json. I can npm install and add the package-lock.json

[jmordica]

Now that the actual errors are fixed related to typings, i'll add the test for the Server typings.

[jmordica]

@sidorares I've added a new test environment for typings specifically and went ahead and included the Server module. So going forward, anyone that creates new typings will be encouraged to add a test in typings/test and modify the tests.json.

Let me know if this seems over-engineered or if you have any questions. Based on your response, I can also add proper tests for the changes in PR #1584.