feat: Log Analytics features of the Cloud Logging API (#60)

feat: Add ConfigServiceV2.CreateBucketAsync method for creating Log Buckets asynchronously
feat: Add ConfigServiceV2.UpdateBucketAsync method for creating Log Buckets asynchronously
feat: Add ConfigServiceV2.CreateLink method for creating linked datasets for Log Analytics Buckets
feat: Add ConfigServiceV2.DeleteLink method for deleting linked datasets
feat: Add ConfigServiceV2.ListLinks method for listing linked datasets
feat: Add ConfigServiceV2.GetLink methods for describing linked datasets
feat: Add LogBucket.analytics_enabled field that specifies whether Log Bucket's Analytics features are enabled
feat: Add LogBucket.index_configs field that contains a list of Log Bucket's indexed fields and related configuration data
docs: Documentation for the Log Analytics features of the Cloud Logging API
PiperOrigin-RevId: 529851525
Source-Link: googleapis/googleapis@1c7ee99
Source-Link: https://github.com/googleapis/googleapis-gen/commit/4a2a3a05b91804333a1b39b635d8fe2243d4b4fd
Copy-Tag: eyJwIjoiLmdpdGh1Yi8uT3dsQm90LnlhbWwiLCJoIjoiNGEyYTNhMDViOTE4MDQzMzNhMWIzOWI2MzVkOGZlMjI0M2Q0YjRmZCJ9