✨ Add support for Pydantic models in Form parameters (#12129)

Revert "⏪️ Temporarily revert "✨ Add support for Pydantic models in `Form` pa…"

This reverts commit 8e6cf9ee9c.

scripts/playwright/request_form_models/image01.py

@@ -0,0 +1,36 @@
+import subprocess
+import time
+
+import httpx
+from playwright.sync_api import Playwright, sync_playwright
+
+
+# Run playwright codegen to generate the code below, copy paste the sections in run()
+def run(playwright: Playwright) -> None:
+    browser = playwright.chromium.launch(headless=False)
+    context = browser.new_context()
+    page = context.new_page()
+    page.goto("http://localhost:8000/docs")
+    page.get_by_role("button", name="POST /login/ Login").click()
+    page.get_by_role("button", name="Try it out").click()
+    page.screenshot(path="docs/en/docs/img/tutorial/request-form-models/image01.png")
+
+    # ---------------------
+    context.close()
+    browser.close()
+
+
+process = subprocess.Popen(
+    ["fastapi", "run", "docs_src/request_form_models/tutorial001.py"]
+)
+try:
+    for _ in range(3):
+        try:
+            response = httpx.get("http://localhost:8000/docs")
+        except httpx.ConnectError:
+            time.sleep(1)
+            break
+    with sync_playwright() as playwright:
+        run(playwright)
+finally:
+    process.terminate()