Add HTTP-specific retry options to azure-functions-durable v2 call_http

Add configurable, durable HTTP failure retries to the azure-functions-durable v2 compatibility package in this repository. This is the Python v2 follow-up to Azure/azure-functions-durable-extension#1984, not a request for generic activity retry support.

Current behavior

Checked azure-functions-durable==2.0.0rc1 (azurefunctions-v2.0.0rc1):

• DurableOrchestrationContext.call_http(method, uri, content=None, headers=None, token_source=None, is_raw_str=False) has no HTTP retry parameter and schedules the built-in HTTP polling sub-orchestration.
• DurableHttpRequest neither accepts nor serializes a retry policy or retryable-status-code list.
• builtin_http_activity returns HTTP error responses rather than treating selected statuses as retryable failures.
• The polling orchestrator calls activities without a retry policy and repeats only for HTTP 202 responses with a Location header.

This package executes HTTP through worker-side built-ins rather than the extension's native HTTP action. Retry support must be implemented in that worker path, not just added to a host-bound JSON field.

Acceptance Criteria

• Expose HTTP-specific retry configuration on call_http, including first retry interval, maximum attempts, backoff coefficient, maximum retry interval, retry timeout, and retryable HTTP status codes.
• Carry the configuration through the request model/serialization and apply durable retries to selected HTTP statuses and retryable transport failures.
• Define and document status-code defaults consistent with .NET HttpRetryOptions (an omitted/empty status-code list retries 4xx/5xx responses when a retry policy is supplied).
• Preserve existing behavior when retry options are omitted, and keep HTTP 202 polling distinct from failure retries.
• Add coverage for retry-then-success, exhausted attempts, excluded status codes, backoff/timeout limits, replay, and interaction with 202 polling.
• Document usage and any intentional differences from .NET HTTP retry semantics.

Related

• Original cross-language tracker: Azure/azure-functions-durable-extension#1984.
• Equivalent Node v4 work: microsoft/durabletask-js#367.
• .NET HttpRetryOptions reference implementation.

Bắt đầu với DurableOrchestrationContext.call_http và đường dẫn HTTP worker trong azure-functions-durable/azure/durable_functions/http/models.py và builtin.py. Theo dõi quá trình tuần tự hóa request và polling orchestrator trước khi so sánh ngữ nghĩa của .NET HttpRetryOptions. Được xem là hoàn thành khi có retry lỗi được cấu hình, vẫn giữ nguyên polling 202 và hành vi khi không có tùy chọn, có tài liệu hướng dẫn sử dụng, và có các test cho thành công, cạn kiệt, loại trừ, giới hạn, replay và tương tác với polling.