new tokens route (#7170)

## [Dashboard] Feature: Add new tokens endpoint and deprecate ERC-20 balances endpoint

## Notes for the reviewer

This PR adds a new endpoint for getting tokens at `/v1/tokens` and marks the existing ERC-20 balances endpoint (`/v1/tokens/erc20/{ownerAddress}`) as deprecated.

## How to test

Verify that the new endpoint is accessible and that the deprecated flag is correctly set for both endpoints in the insight blueprints.

<!-- This is an auto-generated comment: release notes by coderabbit.ai -->

## Summary by CodeRabbit

- **New Features**
  - Introduced a new "Get tokens" endpoint for accessing token data.

- **Bug Fixes**
  - Marked the older ERC-20 balances endpoint as deprecated to guide users toward the updated endpoint.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Author: iuwqyir

apps/playground-web/src/app/insight/insightBlueprints.ts

@@ -77,6 +77,11 @@ export const insightBlueprints: MinimalBlueprintSpec[] = [
       {
         name: "Get ERC-20 balances by address",
         path: "/v1/tokens/erc20/{ownerAddress}",
+        deprecated: true,
+      },
+      {
+        name: "Get tokens",
+        path: "/v1/tokens",
         deprecated: false,
       },
       {