✨ batcher: refactored to add same query batcher

[jfbus]

Description

This PR refactors the batcher to:

• allow simultaneous requests for the same id in the ByID batcher (the former version deadlocked)
• return ErrNotFound in ByID if id was not found
• adds a SameQuery batcher, batching all ReadXRequest that are equal (as defined by reflect.DeepEqual).

Type of Change

Please check the relevant option(s):

• 🐛 Bug fix
• ✨ New feature
• 🧹 Code cleanup or refactor
• 📝 Documentation update
• 🔧 Build or CI-related change
• 🔒 Security fix
• Other (specify):

How Has This Been Tested?

Please describe the test strategy:

• Manual testing
• Unit tests
• Integration tests
• Not tested yet

Checklist

• I have followed the Contributing Guidelines
• I have added tests or explained why they are not needed
• I have updated relevant documentation (README, examples, etc.)
• My changes follow the Conventional Commits specification
• My commits include appropriate Gitmoji

Additional Context