Keyboard/Mouse tests failing after upgrading to version 97

[amaitland]

After upgrading to version 97 (#7) some of the mouse/keyboard tests started failing.

• When run via the debugger and stepping through the code they pass correctly.
• Likely something changed in Chromium.
• Checking through the commands send to CEF vs those generated using puppeteer sharp and nothing stands out so far.
• When running similar code from a WPF application it passes correctly.

Will skip the tests in the short term as the code appears to be working correctly when run under normal conditions (outside the test cases).

[amaitland]

The tests now wait for render idle (wait 500ms when no new paint calls are made).

Reason: Change in Chromium behaviour. I'd speculate some optimisations were made and for super simples pages that render almost instantly we were executing too early.