feature #746 Added Vue3 support (weaverryan)

This PR was squashed before being merged into the master branch.

Discussion
----------

Added Vue3 support

Hi!

Vue3 is now beta. I think Encore should support Vue2 and Vue 3... at least for awhile. The changes needed to make Webpack work with v3 are not that many:

1) Make sure the user installs `vue/compiler-sfc` instead of `vue-template-compiler`
2) require `VueLoaderPlugin` in a slightly different way
3) Add a slightly different "alias" for vue

You can choose the version with a new `version` option to `enableVue()`. Otherwise, it will configure itself correctly if you have vue2 or vue3 installed, or it will (finally) recommend the vue2 install instructions. When v3 comes out, we would change the default recommendation to be v3.

But... getting the code (and test suite) to work with both vue2 and vue3 is quite tricky :).

Commits
-------

40f8ae8 bumping to use vue 2.5.0 to avoid test inconsistency
5abb25d forcing exact low version
06782ae Merge branch 'master' into vue3-support
e51165d correctly clearing logger before asserting
449a0af removing vue3 alias
33d2ac5 fixing bad vue-beta version
24f7652 Upgrading to Webpack 4.22.0 which has a fix for ordering problems
43f66c9 lint fixes
35e508f Forcing vue installation to include @3 or @2 version constraint on yarn add command
d49352b changing order of entrypoints files
d7903e4 updating test hashes
7d2917e fixing missing return
bc182bd fixing lock file
63cfd1a fixing wrong path change in tests
08509da removing vue3 and jsx support for now
c344809 Fixing missing-loader for vue-loader 16
85d42cd working around a bug in vue-loader by putting module styles first
c9f83bc fixing bad test path
6f83868 updating lock file
e702197 hack to test with vue3 and vue2
e376be2 various test fixes
8d07790 WIP Vue3 support

Author: weaverryan

fixtures/vuejs-css-modules/App.vue

@@ -1,7 +1,36 @@
 <template>
-  <div id="app" class="red large justified lowercase block" :class="[$css.italic, $scss.bold, $less.underline, $stylus.rtl, $postcss.hidden]"></div>
+  <div class="red large justified lowercase block" :class="[$css.italic, $scss.bold, $less.underline, $stylus.rtl, $postcss.hidden]"></div>
 </template>
 
+<style module="$css">
+  .italic {
+    font-style: italic;
+  }
+</style>
+
+<style lang="scss" module="$scss">
+  .bold {
+    font-weight: bold;
+  }
+</style>
+
+<style lang="less" module="$less">
+  .underline {
+    text-decoration: underline;
+  }
+</style>
+
+<style lang="styl" module="$stylus">
+  .rtl
+    direction: rtl;
+</style>
+
+<style lang="postcss" module="$postcss">
+  .hidden {
+    visibility: hidden;
+  }
+</style>
+
 <style>
   .red {
     color: red;
@@ -30,33 +59,3 @@
     display: block;
   }
 </style>
-
-
-<style module="$css">
-  .italic {
-    font-style: italic;
-  }
-</style>
-
-<style lang="scss" module="$scss">
-  .bold {
-    font-weight: bold;
-  }
-</style>
-
-<style lang="less" module="$less">
-  .underline {
-    text-decoration: underline;
-  }
-</style>
-
-<style lang="styl" module="$stylus">
-  .rtl
-    direction: rtl;
-</style>
-
-<style lang="postcss" module="$postcss">
-  .hidden {
-    visibility: hidden;
-  }
-</style>

fixtures/vuejs-css-modules/main.js renamed to fixtures/vuejs-css-modules/main_v2.js

@@ -0,0 +1,4 @@
+import { createApp } from 'vue';
+import App from './App'
+
+createApp(App).mount('#app');

fixtures/vuejs-css-modules/main_v3.js

@@ -0,0 +1,4 @@
+import { createApp } from 'vue';
+import App from './App'
+
+createApp(App).mount('#app');