[BUG] Synapse - BigDataPools_Get - does not return `sparkEventsFolder` or `defaultSparkLogFolder`

### API Spec link

https://github.com/Azure/azure-rest-api-specs/blob/main/specification/synapse/resource-manager/Microsoft.Synapse/stable/2021-06-01/bigDataPool.json#L24-L28

### API Spec version

2021-06-01

### Describe the bug

API accepts `sparkEventsFolder` and `defaultSparkLogFolder` on Create/Update, but does not return these fields on subsequent GET operations

### Expected behavior

API returns the fields

### Actual behavior

API does not return the fields

### Reproduction Steps

1. Provision a spark / big data pool with these fields set in the Create request
2. Perform a GET on the pool
3. Check response body, note the missing fields

### Environment

terraform

Start with specification/synapse/resource-manager/Microsoft.Synapse/stable/2021-06-01/bigDataPool.json at lines 24-28 and compare the Create/Update fields with the GET response schema. Confirm how sparkEventsFolder and defaultSparkLogFolder are represented, then validate the specification; done means the GET definition includes both fields consistently with the API behavior.

Written by the indexing model from the issue text.