feat(boto3): Add generic attributes that are common across services

* add generic attributes that are reused across different AWS services.
* request attributes must be created before span creation so streamed-span sampling can consider them.

| Field | Value |
| -- | -- |
| span name | `.`, for example `S3.GetObject` |
| `sentry.op` | `http.client` |
| `sentry.origin` | `auto.http.boto3` |
| `rpc.system.name` | `aws-api` |
| `rpc.service` | modeled service ID |
| `rpc.method` | modeled operation name |
| `cloud.provider` | `aws` |
| `cloud.region` | client region, when available |
| `server.address` | parsed endpoint hostname, when valid |
| `server.port` | endpoint port according to existing URL conventions |

#### Sources

* [https://opentelemetry.io/docs/specs/semconv/cloud-providers/aws-sdk/]()
* [https://github.com/open-telemetry/opentelemetry-python-contrib/blob/main/instrumentation/opentelemetry-instrumentation-botocore/src/opentelemetry/instrumentation/botocore/__init__.py]()