Initial vue 3 support, resolves #440

[tbl0605]

Hi everybody,
Hi @kaskar2008,
I finally decided to share my Vue 3 rewrite of the vue-simple-suggest library. Took me some time to achieve, and there are still some things to do (see below).

What works

• all previous features of vue-simple-suggest should continue to work, except for a few breaking changes. As I haven't tested all the features of vue-simple-suggest, more testing would be welcome.
• npm run dev. You can launch and test same demo as the one found at https://kazanexpress.github.io/vue-simple-suggest/

What still needs to be done

• update the documentation (about the breaking changes)
• npm run build: it compiles "something", but it's probably wrong as-is.
  For now, I simply updated all the webpack + rollup dependencies to support Vue 3, but it all looks like clumsy and incomplete.
  The dist/ directory has been updated but the contents of the generated files may be incorrect (not tested yet).
  Some project files (like lib/window.js) are obsolete now.
  Probably the best solution would be to migrate all the build process to use Vite + rollup. Some help here would be more than welcome.

Breaking changes

• When the user provides its own input, he has to add some listener bindings (provided by the vue-simple-suggest component) to the input element.
  For a custom input component, bind the slot prop "componentField":

    <vue-suggest v-model="model" ... >
      <template v-slot="{ componentField }">
        <my-custom-input v-bind="componentField" ... />
      </template>
    </vue-suggest>

or

    <vue-suggest v-model="model" v-slot="{ componentField }" ... >
      <my-custom-input v-bind="componentField" ... />
    </vue-suggest>

For a native html input, bind the slot prop "field":

    <vue-suggest v-model="model" ... >
      <template v-slot="{ field }">
        <input v-bind="field" type="text" ... />
      </template>
    </vue-suggest>

or

    <vue-suggest v-model="model" v-slot="{ field }" ... >
      <input v-bind="field" type="text" ... />
    </vue-suggest>

This behavior is inspired by the way the vee-validate library makes its Field component work with Vue 3 (see doc) and avoids to hack the internal properties of the Vue VNodes to bind some listeners to them (anyway the Vue 3 VNode API doesn't allow such things anymore).

• the "input" event is now replaced by the "update:modelValue" event (see Vue doc)
• The "emit" option works a bit differently now that Vue 3 supports multiple v-model bindings. When setting the "emit" property to "input", use v-model or @update:modelValue and when setting the "emit" property to "select", use v-model:modelSelect or @update:modelSelect
• The @select event was kept for backward compatibility, but the @update:modelSelect event should be used now

For those who can't wait to try my Vue 3's implementation of the vue-simple-suggest library, you can simply take lib/vue-simple-suggest.vue and lib/misc.js and put them directly in your own projects ;)

Hope my patch will be useful ;)

Thierry.

PR updates:
This PR also includes fix #589 and #590, but not fix #588 (I'm not sure if it's still needed with Vue 3, that needs more testing).