remote allocator support option

[GanymedeNil]

Changes

• Added RemoteAllocatorOption parameter to NewRemoteAllocator.
• Param is a generic option to pass a flag to remote url. If the value is a string and isFlag is true, it will be passed as --name=value. If it's a boolean, it will be passed as --name if value is true. If isFlag is false, it will be passed as name=value. If it's a boolean, it will be passed as name if value is true.

Demo

	devtoolsWsURL := "wss://chrome.browserless.io"
	opts := []chromedp.RemoteAllocatorOption{
		chromedp.Param("token", "YOUR_API_KEY", false),
		chromedp.Param("user-agent", "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/100.0.4896.127 Safari/537.36", true),
	}
	allocatorContext, cancel := chromedp.NewRemoteAllocator(context.Background(), devtoolsWsURL, opts...)

[ZekeLu]

@GanymedeNil Thank you!

Please note that URI components can not be constructed like this: fmt.Sprintf("%s=%s", name, value). They should be escaped.

Besides that, it seems that what the PR does is to construct a special URL for browserless, which I think don't have to be a part of chromedp. We are aware of that the current chromedp does not work with browserless. #990 attempts to address this issue. I want to address the issue in another way. I hope that I can prepare a PR in the next few days, and I hope that you can give it a try when it's ready.

Thank you again!

[ZekeLu]

@GanymedeNil Sorry that I forgot to @ you from #1184. Now that #1184 was merged, I'm going to close this one. Please let me know if you think this one should not be closed.