Fix: trigger not working with some dot.notation modifiers

[dobromir-hristov]

Description

This PR fixes an issue with Vue 3 handling modifiers and keyCodes.

It should now allow passing modifiers the same way as you would do with in Vue. Main fixes are general key modifiers and system key modifiers.

• trigger('keydown.meta.shift.c') - will trigger a cmd + shift + c event listener.
• trigger('keydown.13') - will trigger on enter only, because keyCode is no longer supported.
• trigger('click.right') - will trigger a righclick contextmenu event.
• trigger('click.middle') - will trigger a middle click event.

Context

While writing the docs for form handling I asked myself if we support trigger('keydown.enter') syntax, as I am sure we do in VTU 1, hence we have a dedicated test even - https://github.com/vuejs/vue-test-utils/blob/dev/test/specs/wrapper/trigger.spec.js#L73

However when I re-implemented the same test in VTU 2, it failed. I tried debugging, the trigger code is pretty much the same as VTU 1. I am not sure what is going on here :/

[dobromir-hristov]

Ok well this is apparently keyCode is no longer supported in Vue - https://codepen.io/dobromir/pen/vYNPyPx?editors=1011

[lmiller1990]

code seems good, few random questions. did you find this when using VTU next in a project?

[dobromir-hristov]

So I found the issue while prototyping the docs for form handling. We have complicated cases at work which I got inspired from to dig deeper.

The main issue was that Vue 3 did not seem to have keyCode anymore, so tests would fail with just eventStrings

[lmiller1990]

Looks good to me. I'll approve, hit merge when you are happy.