feat(iota-graphql-rpc): Subscriptions support (#9365)

# Description of change

This PR adds the GraphQL subscription support for `Events` and
`Trnsactions`. Internally it leverages the `InMemory` broker from the
new introduced `iota-indexer-streaming` crate in the monorepo.

Currently this feature is only available for `devnet` & local networks,
as the feature is still in alpha.

## Links to any relevant issues

fixes #8784 

## How the change has been tested

- ran graphql tests
```shell
cargo nextest run -p iota-graphql-rpc --features pg_integration --no-fail-fast --test-threads 1
```
- used the iota binary to spin up an indexer and graphql instance and
test the subscription queries
```
cargo r --features indexer -- start --force-regenesis   --with-indexer --with-graphql
```
- used the integrated graphiQL ui to issue subscription queries
- used a third party graphql client (Postman) to issue the same queries


- [x] Basic tests (linting, compilation, formatting, unit/integration
tests)
- [ ] Patch-specific tests (correctness, functionality coverage)

### Infrastructure QA (only required for crates that are maintained by
@iotaledger/infrastructure)

- [ ] Synchronization of the indexer from genesis for a network
including migration objects.
- [ ] Restart of indexer synchronization locally without resetting the
database.
- [ ] Restart of indexer synchronization on a production-like database.
- [ ] Deployment of services using Docker.
- [ ] Verification of API backward compatibility.

> [!NOTE]
> The following patch does not affect the normal operation of the
indexer, thus tests were skipped.

### Release Notes
- [x] Indexer: introduce to monorepo the `iota-indexer-streaming` crate
which holds logic related to `iota-indexer` streaming capabilities for
streaming `events` and `transactions`.
- [x] GraphQL: Add `Subscription` support for `Event` and
`TransactionBlock`. Currently this feature is only available for
`devnet` & local networks, as the feature is still in alpha.

---------

Co-authored-by: Marc Espin <mespinsanz@gmail.com>

Author: sergiupopescu199

.changeset/wet-deers-drum.md

@@ -0,0 +1,6 @@
+---
+'@iota/graphql-transport': minor
+'@iota/iota-sdk': minor
+---
+
+New subscription API types.

.github/crates-filters.yml

@@ -66,6 +66,8 @@ iota-indexer:
   - "crates/iota-indexer/**"
 iota-indexer-builder:
   - "crates/iota-indexer-builder/**"
+iota-indexer-streaming:
+  - "crates/iota-indexer-streaming/**"
 iota-json:
   - "crates/iota-json/**"
 iota-json-rpc:

Cargo.lock

@@ -99,6 +99,7 @@ members = [
   "crates/iota-http",
   "crates/iota-indexer",
   "crates/iota-indexer-builder",
+  "crates/iota-indexer-streaming",
   "crates/iota-json",
   "crates/iota-json-rpc",
   "crates/iota-json-rpc-api",
@@ -419,6 +420,7 @@ iota-grpc-types = { path = "crates/iota-grpc-types" }
 iota-http = { path = "crates/iota-http" }
 iota-indexer = { path = "crates/iota-indexer" }
 iota-indexer-builder = { path = "crates/iota-indexer-builder" }
+iota-indexer-streaming = { path = "crates/iota-indexer-streaming" }
 iota-json = { path = "crates/iota-json" }
 iota-json-rpc = { path = "crates/iota-json-rpc" }
 iota-json-rpc-api = { path = "crates/iota-json-rpc-api" }

Cargo.toml

@@ -41,6 +41,7 @@ tap.workspace = true
 tempfile.workspace = true
 thiserror.workspace = true
 tokio = { workspace = true, features = ["rt-multi-thread"] }
+tokio-stream.workspace = true
 tokio-util = { workspace = true, features = ["rt"] }
 toml.workspace = true
 tower.workspace = true
@@ -54,6 +55,7 @@ iota-graphql-config.workspace = true
 iota-graphql-rpc-client.workspace = true
 iota-graphql-rpc-headers.workspace = true
 iota-indexer.workspace = true
+iota-indexer-streaming.workspace = true
 iota-json.workspace = true
 iota-json-rpc.workspace = true
 iota-json-rpc-api.workspace = true