Feat/custom token rates for endpoints

[rubentalstra]

Summary

Closes: #1633

This pull request introduces custom token and cache override functionality for different models, updates the configuration loading process, and adds type definitions for token rates in the api and packages/data-provider directories. The most important changes include adding new functions to set custom overrides, modifying the cache multiplier retrieval logic, and updating the configuration schema.

Custom override functionality:

• api/models/tx.js: Added setCustomTokenOverrides and setCustomCacheOverrides functions to allow overriding default token and cache multipliers for specific models. [1] [2]

Cache multiplier retrieval logic:

• api/models/tx.js: Updated the getCacheMultiplier function to check for custom cache overrides before falling back to default values.

Configuration loading:

• api/server/services/AppService.js: Added loadTokenRatesConfig to the configuration loading process to handle custom token rates. [1] [2]
• api/server/services/Config/loadTokenRatesConfig.js: Implemented the loadTokenRatesConfig function to merge user and default token rates and apply custom overrides.

Type definitions:

• packages/data-provider/src/config.ts: Added type definitions for token rates (TTokenCost and TModelTokenRates) and updated the configuration schema to include token rates. [1] [2]

Change Type

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• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update
• Translation update

Testing

Please describe your test process and include instructions so that we can reproduce your test. If there are any important variables for your testing configuration, list them here.

Test Configuration:

Checklist

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• My code adheres to this project's style guidelines
• I have performed a self-review of my own code
• I have commented in any complex areas of my code
• I have made pertinent documentation changes
• My changes do not introduce new warnings
• I have written tests demonstrating that my changes are effective or that my feature works
• Local unit tests pass with my changes
• Any changes dependent on mine have been merged and published in downstream modules.
• A pull request for updating the documentation has been submitted.