rgw: support bucket notification API

[yuvalif]

implement the following bucket APIs to manage bucket notifications:
https://docs.ceph.com/en/latest/radosgw/s3/bucketops/#create-notification
https://docs.ceph.com/en/latest/radosgw/s3/bucketops/#delete-notification
https://docs.ceph.com/en/latest/radosgw/s3/bucketops/#get-list-notification

[phlogistonjohn]

Thanks! CCing @leseb and @thotz as our experts on rgw for scoping. If either of think it's a good fit for go-ceph we'll label this issues appropriately.

[thotz]

Thanks! CCing @leseb and @thotz as our experts on rgw for scoping. If either of think it's a good fit for go-ceph we'll label this issues appropriately.

Actually @yuvalif is the real expert here. He is part of RGW team and working on rook/rook#8426 in Rook related to this feature

[yuvalif]

without a specific go ceph API we have to use the AWS SDK one: https://pkg.go.dev/github.com/aws/aws-sdk-go@v1.35.24/service/s3#PutBucketNotificationInput

however, this does not include some extensions that we made to the API that works only for the RGW.