[meta bug] selector 2 readable locators issues

[mxschmitt]

Scope: This don"t need to be essentially upstream bugs, but most likely.

1:

Actual: locator("body").locator("iframe")
Expected: locator("body").frame_locator("iframe").locator("button")

2:

Actual: frameLocator('iframe')
Expected: FrameLocator("iframe")

3:

Looks the same as 1