feat: Rebrand Polkadot/Substrate references to PezkuwiChain

This commit systematically rebrands various references from Parity Technologies'
Polkadot/Substrate ecosystem to PezkuwiChain within the kurdistan-sdk.

Key changes include:
- Updated external repository URLs (zombienet-sdk, parity-db, parity-scale-codec, wasm-instrument) to point to pezkuwichain forks.
- Modified internal documentation and code comments to reflect PezkuwiChain naming and structure.
- Replaced direct references to  with  or specific paths within the  for XCM, Pezkuwi, and other modules.
- Cleaned up deprecated  issue and PR references in various  and  files, particularly in  and  modules.
- Adjusted image and logo URLs in documentation to point to PezkuwiChain assets.
- Removed or rephrased comments related to external Polkadot/Substrate PRs and issues.

This is a significant step towards fully customizing the SDK for the PezkuwiChain ecosystem.

bridges/testing/README.md

@@ -17,10 +17,10 @@ Prerequisites for running the tests locally:
 - ensure that you have [`node`](https://nodejs.org/en) installed. Additionally, we'll need the globally installed
   `pezkuwi/api-cli` package. Use `yarn global add @pezkuwi/api-cli` to install it.
 
-- build Substrate relay by running `cargo build -p substrate-relay --release` command in the
+- build Bizinikiwi relay by running `cargo build -p bizinikiwi-relay --release` command in the
   [`parity-bridges-common`](https://github.com/paritytech/parity-bridges-common) repository clone;
 
-- copy the `substrate-relay` binary, built in the previous step, to `~/local_bridge_testing/bin/substrate-relay`;
+- copy the `bizinikiwi-relay` binary, built in the previous step, to `~/local_bridge_testing/bin/bizinikiwi-relay`;
 
 On Mac, you'll also need to do the following: