Date Comparisons

[robmarti]

This PR should fix some date related issues.

Adjust DateTime related grammar parts:

• use the dayjs format() function which returns an ISO8601 (allows for lexicographical comparison between dates)
• pass the correct substring to dayjs (previously, the last character of date strings was omitted)

Adjust evaluation logic:

• allow for inequality checks between non-numerical types

[mikepringle]

@ThomasHambach is it possible to get this updated and merged in? Looks like you need to migrate from SonarCloud to sonarqube-scan-action.

[ThomasHambach]

@mikepringle yes! Been a bit swamped at the full time job. I would be happy if you have the time for a PR, if not I can do it over the weekend.

[mikepringle]

PR is up