ZD_Record support for addError and hasErrors SObject class methods

Add support to the ZD_Record class to handle the addError, hasErrors, and getErrors methods for the record itself. field level errors will be handled later.

https://help.salesforce.com/s/articleView?id=release-notes.rn_apex_trackErrors.htm&release=228&type=5

https://developer.salesforce.com/docs/atlas.en-us.apexref.meta/apexref/apex_methods_system_sobject.htm

Start with the ZD_Record class and compare its current behavior with the Salesforce SObject documentation linked in the issue. Check the Apex track-errors release notes and the SObject method reference for addError, hasErrors, and getErrors. Done means record-level support for all three methods, while field-level errors remain out of scope.

Written by the indexing model from the issue text.