[Task]: Add examples on the usage of Notarization with the gas station

[itsyaasir]

We need to demonstrate the gas-station usage in an additional example.

Setting up a local Gas-Station service with and without Bearer authentication is a bit tricky at the moment.

Gas-Station without Bearer authentication

Check out the latest gas-station dev branch.

The gas-station without Bearer authentication can be started like this (in the gas-station/docker folder):

> generate-sample-config --config-path config.yaml --docker-compose -n testnet
Unable to find image 'iotaledger/gas-station-tool:latest' locally
latest: Pulling from iotaledger/gas-station-tool
cc41ef31545f: Already exists 
607d3ac95693: Pull complete 
83ba0c981770: Pull complete 
Digest: sha256:c773754bef65bcc5bc3375c1e327f84db477a006dca6f5dafb7c837c2a396493
Status: Downloaded newer image for iotaledger/gas-station-tool:latest
Generated a new IOTA address. If you plan to use it, please make sure it has enough funds: '0x28664b7cc94f2fb82845145acea06c1d7a3277fb1b1d5b764f2b020987654321'

> iota client switch --env testnet
Active environment switched to [testnet]

> iota client faucet --address 0x28664b7cc94f2fb82845145acea06c1d7a3277fb1b1d5b764f2b020987654321
Request successful. It can take up to 1 minute to get the coin. Run iota client gas to check your gas coins.

> docker compose up
[+] Running 3/3
 ✔ Network docker_default       Created                                                                                                                                                                                     0.0s 
 ✔ Container gas-station-redis  Created                                                                                                                                                                                     0.0s 
 ✔ Container iota-gas-station   Created                                                                                                                                                                                     0.0s 
Attaching to gas-station-redis, iota-gas-station
gas-station-redis  | Starting ...
...
...

On client side, the main difference is to use executeWithGasStation instead of buildAndExecute like this:

const { output: notarization } = await notarizationClient
        .createLocked()
        .withStringState("Undeletable data", "v1")
        .withDeleteLock(TimeLock.withUnlockAt(delete_unlock_at))
        .withImmutableDescription("This can not be changed any more")
        .withUpdatableMetadata("This can be updated")
        .finish()
        .executeWithGasStation(notarizationClient, "http://localhost:9527/", new DefaultHttpClient());

Using Bearer authentication

Having already performed all the preparation steps described above, you need to add an entry for the GAS_STATION_AUTH env variable in the environment section of the docker/docker-compose.yml file:

    environment:
      - CONFIG_PATH=/app/config.yaml
      - RUST_BACKTRACE=1
      - GAS_STATION_AUTH=${GAS_STATION_AUTH}

After having added this, the gas station needs to be started like this (we are using Bearer token "12345678" for example purposes here):

GAS_STATION_AUTH="12345678" docker compose up

On client side, the Bearer token needs to be provided using the withAuthToken function:

// Create default GasStationParams with AuthToken 
const gasStationParams = new GasStationParams().withAuthToken("12345678");

// Print to console for debug purposes
console.log ("gasStationParams.headers:"); // Error: null pointer passed to rust
gasStationParams.headers.forEach((value: boolean, key: string) => {
        console.log(key, value);
    });
console.log (`gasStationParams.gasReservationDuration: ${gasStationParams.gasReservationDuration}`);

const { output: notarization } = await notarizationClient
        .createLocked()
        .withStringState("Undeletable data", "v1")
        .withDeleteLock(TimeLock.withUnlockAt(delete_unlock_at))
        .withImmutableDescription("This can not be changed any more")
        .withUpdatableMetadata("This can be updated")
        .finish()
        .executeWithGasStation(notarizationClient, "http://localhost:9527/", new DefaultHttpClient(), gasStationParams);

Open questions

Ideally we would only have a single source of truth for examples on the usage of IOTA products with gas-station. Not sure how to accomplish this.

Option 1 : Just have verbose examples for Notarization (or Identity, or ...) and reference it from other products.
Option 2: Our Product-Integration docs (not existing at the moment)