WIP feat: Add vue 3 support

[crutch12]

solves #315

What's new:

• updated dependencies
• updated vue v-modal usage (https://v3.vuejs.org/guide/migration/v-model.html)
• added emits option (https://v3.vuejs.org/guide/component-custom-events.html)
• renamed transition class names (https://v3.vuejs.org/guide/migration/transition.html)
• fixed transition-group usage (TransitionGroup doesn't render a wrapper element by default in Vue 3, it uses a Fragment vuejs/docs#648)
• mounting vue app using createApp function (https://v3.vuejs.org/api/global-api.html#createapp)
• removed noValueToCustomElem prop and added new slots support (https://v3.vuejs.org/guide/migration/slots-unification.html)
• renamed beforeDestroy -> beforeUnmount
• updated unit tests (dependencies, api calls)
• updated eslint rules (v-bind="object" is now order-sensitive - https://v3.vuejs.org/guide/migration/v-bind.html)
• v-click-outside doesn't support vue 3, so I've created a local copy until lib will be ready to use

TODO:

• nuxt doesn't support vue3 (Vue 3 Support nuxt/nuxt#5708)
• vue-test-utils-next doesn't support setData yet (setData vuejs/test-utils#228)
• rewrite mixin keyboard-accessibility.js using composition-api methods

[crutch12]

@WilliamDASILVA I think we should create @next branch (and npm tag) for this update

[victorybiz]

Any updates on Support of Vue 3?

[aGrahamAtFuji]

any more updates for support of Vue 3?

[issei-m]

Any update?

[cahyowhy]

already one year here :(

[crutch12]

@cahyowhy as I can see @WilliamDASILVA merged this branch and published 3.0.0-alpha.0 - https://www.npmjs.com/package/vue-ctk-date-time-picker/v/3.0.0-alpha.0