feat: Add mc_getAssetBalance RPC method

[SIDDHANTCOOKIE]

Addresses 'An RPC method for a single asset balance' from the ychain roadmap. Stacked on feature/native-multi-asset.

[coderabbitai]

Important

Review skipped

Auto reviews are disabled on base/target branches other than the default branch.

🗂️ Base branches to auto review (2)

• main
• develop

---

Please check the settings in the CodeRabbit UI or the .coderabbit.yaml file in this repository. To trigger a single review, invoke the @coderabbitai review command.

⚙️ Run configuration

• Configuration used: Repository: StabilityNexus/MiniChain/.coderabbit.yaml
• Review profile: ASSERTIVE
• Plan: Advanced
• Run ID: 2b9b6a09-a9d3-4cb9-9cf9-389240f55e29

---

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

Use the checkbox below for a quick retry:

• 🔍 Trigger review

• Autofix · Keep fixing CodeRabbit findings and required CI, and resolving merge conflicts

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

---

_{Comment @coderabbitai help to get the list of available commands.}