Enable access to error message details (what,why,...)

[exalate-issue-sync]

Often we need to access any of the "what why consequences countermeasures" ErrorMessage contract fields. Currently, it is only possible to parse those from an already (initially) serialized ErrorMessage, by using the template format 

[https://github.com/vmware/versatile-data-kit/blob/main/projects/vdk-core/src/vdk/internal/core/errors.py#L125] that is implementation-specific.

Suggestion:

Keep the reference to the ErrorMessage instance, so that the four contract fields are accessible when catching the exception [https://github.com/vmware/versatile-data-kit/blob/main/projects/vdk-core/src/vdk/internal/core/errors.py#L68] 

 

Acceptance criteria:

In case a BaseVdkError is catched, then we can retrieve any of the "what why consequences countermeasures" fields - without the need to parse them from string. Both vdk-core change is released, and supercollider-vdk "WHAT HAPPENED" (see telemetry plugin) parsing is switched to direct field retrieval.

[sabadzhiev]

Triaged. We will keep it, as being an feature that we will discus and decide if it needs to be fixed as part of: #2408