Convert `ErrorCodeV1` error codes (99 remaining) to new ("V2") variant

[tatu-at-datastax]

Older code (mostly Collection-related) uses ErrorCodeV1 and JsonApiException for reporting problems.
But we have newer facilities for doing this: ErrorCode and more granular exception/code hierarchy, including external templating (errors.yaml).

So let's start converting: 116 to go, with hundreds of usages.

[tatu-at-datastax]

First batch removed: 112 to go.