Improve UX when invalid drawing happens

[ddjnw1yu]

The following cases will cause some UX issues:

• Pressing ESC will cancel a drawing, but the tool button will still be selected.
• Drawing a point (clicking on the same position twice) when the line tool is selected. The drawing will be cancelled, but the tool button will still be selected.
• Drawing a point/line when the polygon tool is selected. The drawing will be cancelled, but the tool button will still be selected.
• Pressing Enter/Return when a drawing is not completed. The drawing will be cancelled, but the tool button will still be selected.

The reason is that we switched from using the built-in toolbar to using direct API calls. Some of the keyboard and mouse support no longer exist.

[alan-wu]

The implementation needs to be improved on this. the number of callbacks increases the more I change the draw tool. The remove event listener will not work because the callback (second argument) in the addEventLister itself is an anonymous function.

[alan-wu]

Thanks, much better and work well.