an idea for prefering double clicks

[coolcorey]

Checklist

Please put "X" in the below checkboxes that apply::

• If committing a bugfix, I have tested it in different browsers (Chrome, Firefox, Safari).
• If committing a new feature, I have first submitted an issue (Please note: you are free to open PRs for non-issued features, but opening an issue increases your chance of a successful PR).
• If committing a new feature, I have also written an appropriate test suite for it.

I have tested the following:

• Qalendar component in month mode.
• Qalendar component in week mode.
• Qalendar component in day mode.
• All of the above modes on emulated mobile view.
• Dragging and dropping events.
• Resizing events in day/week modes.
• Clicking events to open event dialog.

This PR solves the following problem**.

Allows user to specify that they only want to listen for double click events, then only emits on double click events. I do see that you are deprecating the day-was-clicked event, but I wasn't seeing that it was implemented yet.

How to test this PR**.

Double click a day where the config option emitOnDoubleClick is set to true. Note that with this option set to true, single clicks are not emitted.

I can flesh out this PR more if you are interested in this idea.

#244