Provide AWS Lambda Layer ARN in package

### Problem Statement

I want to utilize AWS Lambda Layers in my setup but it's hard to know what features are included in the layer's versions. This way it's hard to track official Sentry package releases together with the layer's versions.

### Solution Brainstorm

If we could provide the AWS Lambda Layer version inside of the `@sentry/serverless` package we can use this to get matching version in out Lambda functions.

It could be a JSON file that just contains the ARN per region.
Example:

```json5
{
"us-east-1": "arn:aws:lambda:us-east-1:943013980633:layer:SentryNodeServerlessSDK:184",
"us-east-2": "arn:aws:lambda:us-east-2:943013980633:layer:SentryNodeServerlessSDK:184",
/* ... */
}
```