[Refactor] embedded Service to be ServiceId

[red-0ne]

Summary

Update Session.Header.Service references to Session.Header.ServiceId to comply with Poktroll updates.

Issue

Poktroll refactored all embedded Service to ServiceId. ShannonSDK is affected by Session.Header.Service change and needs to be updated.

Type of change

Select one or more:

• New feature, functionality or library
• Bug fix
• Code health or cleanup
• Documentation
• Other (specify)

Sanity Checklist

• I have tested my changes using the available tooling
• I have commented my code
• I have performed a self-review of my own code; both comments & source code
• I create and reference any new tickets, if applicable
• I have left TODOs throughout the codebase, if applicable