materialize-motherduck: additional logs for diag, json ignore_errors=…

[mdibaiee]

…false

Description:

• set ignore_errors=false in read_json which seems like a issue we have had (although not confirmed whether this has actually been triggered ever)
• add additional diagnostic statistics logs so that we can know why data is missing: is the connector sending the right amount of insertions, updates and deletes? If so, the issue is in motherduck, otherwise it is in our connector

Workflow steps:

(How does one use this feature, and how has it changed)

Documentation links affected:

(list any documentation links that you created, or existing ones that you've identified as needing updates, along with a brief description)

Notes for reviewers:

(anything that might help someone review this PR)