Fix DELIMITER handling

[epenet]

Checklist

• I have read the Contributing Guide
• I have checked to ensure this does not introduce an unintended breaking changes
• I have considered appropriate testing for my change

Description

Fixes #7
Extracted from DbUp/DbUp#661

Needs:

• Expose GetCurrentCommandTextFromBuffer DbUp#790

[epenet]

@droyad, from what I can work out, the CI is failing from something outside of this PR.

An issue pushing to GitHub packages:
warn : Your request could not be authenticated by the GitHub Packages service. Please ensure your access token is valid and has the appropriate scopes configured.

and an issue reporting on the test results
Error: HttpError: Resource not accessible by integration

[droyad]

@epenet Thanks for having a look. Not sure what's going on, I'm still messing around with the builds at the moment..

Builds and tests pass, so might as well merge it.

[epenet]

Thanks