Enumerations in public interfaces need a catch-all type

[jan-auer]

• fix(server): Forward-compatible AttachmentType #1638
• Add unknown to RuleType and SamplingMode fix(sampling): Forward compatibility for config #1641
• Check for more enumerations without a catch-all variant
• Add Other(u8) to SpanStatus feat(common): Add catch-all status code variant for SpanStatus #1737
  @jjbayer will check if we need different behavior in processing relays, and how.
• Add Unknown(String) to SessionStatus. Do not extract metrics for unknown, but do forward session payloads. Remove in processing Relays. // pr: feat(general): Add unknown SessionStatus variant #1736
• Add Unknown(String) variant to relay_profiling::MeasurementUnit. Let Profiling team decide whether or not to drop unknowns in processing Relays. -> Not necessary right now because we don't parse profiles in non-processing relays.
• BucketValue: Drop buckets with unknown type on deserialization. // bucketvalues are only sent from relay to relay, so no need forward compatibility in external relays
• All PII config enums (see notion doc for details): skip rule on deserialization.
  Moved to separate issue: Make pii config forward-compatible #1751
• RateLimitScope: Skip unknown scopes (e.g. by skipping rule on deserialization). -> This already has a fallback via QuotaScope, see

  relay/relay-quotas/src/rate_limit.rs

  Lines 122 to 123 in 337a8a0

  	// For unknown scopes, assume the most specific scope:
  	QuotaScope::Unknown => RateLimitScope::Key(scoping.project_key),

[jjbayer]

Found the following problematic enums (internal doc): https://www.notion.so/sentry/Forward-compatibility-of-enums-5eafecc16a014cbab13dbab3791ccef3