feat: add getheaderbyhash method to grpc-js (#5942)

Description
---
add `getHeaderByHash` to the exported method, so we can search by hash
in the tari explorer.

Motivation and Context
---

How Has This Been Tested?
---

What process can a PR reviewer use to test or verify this change?
---

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Breaking Changes
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- [x] None
- [ ] Requires data directory on base node to be deleted
- [ ] Requires hard fork
- [ ] Other - Please specify

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clients/nodejs/base_node_grpc_client/src/index.js

@@ -44,6 +44,7 @@ function Client(address = "127.0.0.1:18142") {
     "getTokens",
     "getNetworkDifficulty",
     "getActiveValidatorNodes",
+    "getHeaderByHash"
   ];
   methods.forEach((method) => {
     this[method] = (arg) => this.inner[method]().sendMessage(arg);