TDL-21347 Filter non-ascii non-alphanumeric metric names

[bryantgray]

Description of change

Custom event-scoped metrics with non-ascii non-alphanumeric names can be created in the GA4 console. These characters are currently incompatible with Google's Data API.

example:
The parentheses in a metric named conversion:(other) causes this response:

CRITICAL 400 Metric names must only contain letters, numbers, or _. Received a metric name = conversions[(other)]

See: https://support.google.com/analytics/thread/176551995/conversion-event-api-calls-should-use-event-id-not-name-sessionconversionrate-conversion-event-name

This change filters the bad metric names so a connection can successfully complete the check. The bad metrics will be marked unsupported in field selection.

Manual QA steps

• Verified discovery can complete with the bad metrics filtered.

Risks

• May cause confusion due to custom metrics that include the incompatible characters showing as unsupported.

Rollback steps

• revert this branch