feat: add projects billing fields list methods

[fern-api]

• Adds new response types for listing billing fields with deployment item enums
• Implements synchronous and asynchronous client methods for billing fields operations
• Updates module exports and documentation to include the new billing fields functionality

[Copilot]

Pull Request Overview

This PR adds new billing fields functionality to the Deepgram Python SDK by implementing list methods for projects billing fields. The changes introduce endpoints to retrieve accessors, deployment types, tags, and line items used for billing data within specified time periods.

• Adds new response types for listing billing fields with deployment item enums
• Implements synchronous and asynchronous client methods for billing fields operations
• Updates module exports and documentation to include the new billing fields functionality

Reviewed Changes

Copilot reviewed 12 out of 12 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
src/deepgram/types/list_billing_fields_v1response_deployments_item.py	Defines deployment type union for billing fields response
src/deepgram/types/list_billing_fields_v1response.py	Implements main response model for billing fields with accessors, deployments, tags, and line items
src/deepgram/types/__init__.py	Exports new billing fields response types
src/deepgram/requests/list_billing_fields_v1response.py	Defines request parameters for billing fields endpoints
src/deepgram/requests/__init__.py	Exports new billing fields request parameters
src/deepgram/manage/v1/projects/billing/fields/raw_client.py	Implements raw HTTP client for billing fields operations
src/deepgram/manage/v1/projects/billing/fields/client.py	Implements high-level client wrapper for billing fields with examples
src/deepgram/manage/v1/projects/billing/fields/__init__.py	Module initialization for billing fields
src/deepgram/manage/v1/projects/billing/client.py	Integrates fields client into billing client hierarchy
src/deepgram/manage/v1/projects/billing/__init__.py	Exports fields module in billing package
src/deepgram/__init__.py	Adds billing fields types to main package exports
reference.md	Documents the new billing fields list endpoint with usage examples

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[Copilot]

Pull Request Overview

Copilot reviewed 13 out of 13 changed files in this pull request and generated 1 comment.

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[Copilot]

The union with typing.Any makes this type definition ineffective for type checking. Consider using only the literal values or adding a clear comment explaining why typing.Any is necessary. This allows any value to be accepted, which defeats the purpose of having predefined literals.

Suggested change

	ListBillingFieldsV1ResponseDeploymentsItem = typing.Union[
	typing.Literal["hosted", "beta", "self-hosted", "dedicated"], typing.Any
	]
	ListBillingFieldsV1ResponseDeploymentsItem = typing.Literal["hosted", "beta", "self-hosted", "dedicated"]