After the context has been disposed we can't route any callbacks to it
because
it is not in the map, so the assertion doesn't make sense as it always
ends up in
the top level session.
Fixes the following error:
```
pw:browser <closing ws> Closing websocket due to failed onmessage callback. eventData={"type":"success","id":32,"result":{}} e=Assertion error Error: Assertion error
pw:browser at assert (/home/yurys/playwright/packages/playwright-core/src/utils/debug.ts:21:11)
pw:browser at BidiSession.dispatchMessage (/home/yurys/playwright/packages/playwright-core/src/server/bidi/bidiConnection.ts:229:13)
pw:browser at BidiConnection.call [as _dispatchMessage] (/home/yurys/playwright/packages/playwright-core/src/server/bidi/bidiConnection.ts:93:25)
```
This pull request introduces initial support for the WebDriver BiDi
protocol in Playwright. The primary goal of this PR is not to fully
implement BiDi but to experiment with the current state of the
specification and its implementation. We aim to identify the biggest
gaps and challenges that need to be addressed before considering BiDi as
the main protocol for Playwright.
