Improve sourcemap upload duration for multi-stage builds

[lforst]

I'll limit this issue to Next.js because it is a super-set of everything else.

In high-level frameworks there are often multiple build-passes the framework does. This can cause the Sentry plugin to pick up and upload the same files multiple times, potentially leading to unnecessarily long uploads.

Brainstorming a solution:

• Allow to pass in a build-id into the plugin that will associate multiple bundler runs with the same build, allowing us to store and deduplicate files to avoid double uploading.
• Telemetry-wise, it would probably also good to share a trace id between these runs.

Related getsentry/sentry-javascript#14132