Abstract WC/SDK logic outside of BackgroundBridge and RPCMethodMiddleware

### What is this about?

Currently, there are areas in both `BackgroundBridge` and `RPCMethodMiddleware` files where there is hardcoded logic that is unique to WC/SDK features. These files should be agnostic to the services that use them and feature specific logic should be handled outside or passed in during initialization.

Here are a few examples of these areas that should be abstracted
- In BackgroundBridge - https://github.com/MetaMask/metamask-mobile/blob/e0a2253824aeaf4ce98f109b923cfb76c885a932/app/core/BackgroundBridge/BackgroundBridge.js#L88
- In RPCMethodMiddleware - https://github.com/MetaMask/metamask-mobile/blob/e0a2253824aeaf4ce98f109b923cfb76c885a932/app/core/RPCMethods/RPCMethodMiddleware.ts#L130

### Scenario

_No response_

### Design

_No response_

### Technical Details

- Abstract WC/SDK logic outside of RPCMethodMiddleware and BackgroundBridge

### Threat Modeling Framework

_No response_

### Acceptance Criteria

- BackgroundBridge and RPCMethodMiddleware is kept feature agnostic

### Stakeholder review needed before the work gets merged

- [ ] Engineering (needed in most cases)
- [ ] Design
- [ ] Product
- [ ] QA (automation tests are required to pass before merging PRs but not all changes are covered by automation tests - please review if QA is needed beyond automation tests)
- [ ] Security
- [ ] Legal
- [ ] Marketing
- [ ] Management (please specify)
- [ ] Other (please specify)

### References

- An issue related to hardcoded logic - https://github.com/orgs/MetaMask/projects/60/views/6?pane=issue&itemId=61033941

Start with the referenced sections of app/core/BackgroundBridge/BackgroundBridge.js and app/core/RPCMethods/RPCMethodMiddleware.ts, then trace the WC/SDK-specific logic they contain. Define the abstraction or initialization inputs needed to keep both components feature agnostic; done means the acceptance criterion is met without changing their core behavior.

Written by the indexing model from the issue text.