[BUG] FrameLocator type is not exported

[evan-dickinson]

Context:

• Playwright Version: 1.22
• Operating System: Linux
• Python version: 3.8.0
• Browser: n/a
• Extra: n/a

Code Snippet

from playwright.async_api import FrameLocator, Page


def locate_my_iframe(page: Page) -> FrameLocator:
    return page.frame_locator('some_complex_selector')

Describe the bug

Because the FrameLocator type isn't exported from playwright.async_api (nor from sync_api), I can't use it as the type of a return value or function parameter. The code above fails Mypy with the error Module 'playwright.async_api' has no attribute 'FrameLocator' [attr-defined].

FrameLocator is a documented part of the API, so it seems like it should be exported.