feat(mssql): upgrade to tedious 18

[WikiRik]

Pull Request Checklist

• Have you added new tests to prevent regressions?
• If a documentation update is necessary, have you opened a PR to the documentation repository?
• Did you update the typescript typings accordingly (if applicable)?
• Does the description below contain a link to an existing issue (Closes #[issue]) or a description of the issue you are solving?
• Does the name of your PR follow our conventions?

Description of Changes

Tedious 18 now ships with first-party typings so we can remove @types/tedious.

Drafting this for now since I want to check what we've put in the docs for TypeScript usage of mssql.
EDIT: This will be done as part of the documentation surrounding the dialect extraction

List of Breaking Changes

People that use TypeScript should upgrade to v18 as well. And they can remove @types/tedious

[WikiRik]

This is ready to be reviewed, but not for merging yet since I still need to check docs

[WikiRik]

@lohart13 what do you think, shall I rebase this once you have extracted @sequelize/mssql away?

[lohart13]

@WikiRik if you're ready to merge this, go ahead. The mssql split is still WIP.