feat(core): Apply scope attributes to metrics

[github-actions]

Note

The pull request "feat(core): Apply scope attributes to metrics" was created by @Lms24 but did not reference an issue. Therefore this issue was created for better visibility in external tools like Linear.

• ref(core): Use serializeAttributes for metric attribute serialization
• fix undefined and null values when fallback is true
• allow stringifying undefined?
• fix tests
• skip undefined if fallback is skip-undefined
• feat(core): Apply scope attributes to logs

[linear]

JS-1426