OpenTelemetry: move OTel-related packages into shared directory

We should move OTel-related packages to `platform/packages/shared/opentelemetry` to logically group them. [Currently](https://github.com/elastic/kibana/pull/225417) the packages are:

- `@kbn/telemetry`
- `@kbn/telemetry-config`
- `@kbn/tracing`
- `@kbn/tracing-config`
- `@kbn/inference-tracing`
- `@kbn/inference-tracing-config`

