fix(sdk)!: allow for zero-based blueprint_id

[shekohex]

This pull request includes several changes to the sdk module to improve the handling of service_id and streamline the configuration process for Tangle blueprints. The most important changes include making service_id optional, adjusting related methods, and removing redundant checks.

Changes to service_id handling:

• sdk/src/config/gadget_config.rs: Modified service_id to be optional in GadgetConfiguration and updated the service_id method to return the correct type. [1] [2]
• sdk/src/config/protocol.rs: Updated TangleInstanceSettings to make service_id an Option<u64> and added a note for registration mode.

Configuration adjustments:

• sdk/src/config/mod.rs: Adjusted the load_inner function to handle service_id conditionally based on the registration mode.

Codebase simplification:

• sdk/src/runners/tangle.rs: Removed redundant checks for blueprint_id in TangleConfig to allow for zero-based blueprint_ids. [1] [2]