fix: small fix and refactor after testing EkuboV2 (#188)

* fix: add `balance_owner` attribute for ekubo_v2 components

* refactor: rename `ekubo` into `ekubo-v2`

* refactor: freeze `substreams-helper` version in ekubo V2 module

* docs: improve integration test comment

* docs: add TODO to remove `balance_owner` in favor of `AccountBalances`

---------

Co-authored-by: zizou <111426680+flopell@users.noreply.github.com>

substreams/ethereum-ekubo-v2/src/pb/mod.rs

@@ -0,0 +1,6 @@
+// @generated
+// @@protoc_insertion_point(attribute:ekubo)
+pub mod ekubo {
+    include!("ekubo.rs");
+    // @@protoc_insertion_point(ekubo)
+}