[WIP] Cleanup Global Error handler

[lalitb]

Fixes #2175

Changes

In Progress. TODO:

• Move TraceError and LogError from API to SDK. API should be only returning no-op constructs, and not the error objects. MetricsError is still being used in its API, so need to be handled separately.
• Better handling for <signal>Error, CoW and few other types inside otel macros. As of now, the called needs to use format! to invoke their Debug impl, which is cumbersome.

For future improvement:

• Allow applications/users to plugin their log handler.

Please provide a brief description of the changes here.

Merge requirement checklist

• [ ] CONTRIBUTING guidelines followed
• [ ] Unit tests added/updated (if applicable)
• [ ] Appropriate CHANGELOG.md files updated for non-trivial, user-facing changes
• [ ] Changes in public API reviewed (if applicable)