DEV: Move pretty-text into vendor and use that (#13273)

In Ember CLI addons get put into the vendor bundle, as opposed to their
own bundle like we're doing in the Rails app. We never use pretty-text
without our vendor bundle so this should have no difference on
performance.

We need to keep the pretty-text bundle for server side cooking.

app/assets/javascripts/discourse/tests/test_helper.js

@@ -17,7 +17,6 @@
 // Our base application
 //= require vendor
 //= require discourse-shims
-//= require pretty-text-bundle
 //= require markdown-it-bundle
 //= require application
 //= require admin

app/assets/javascripts/vendor.js

@@ -27,3 +27,4 @@
 //= require virtual-dom-amd
 //= require intersection-observer
 //= require discourse-shims
+//= require pretty-text-bundle

app/views/layouts/application.html.erb

@@ -29,7 +29,6 @@
       <%= preload_script_url ExtraLocalesController.url('overrides') %>
     <%- end %>
     <%= preload_script "vendor" %>
-    <%= preload_script "pretty-text-bundle" %>
     <%= preload_script "application" %>
     <%- Discourse.find_plugin_js_assets(include_official: allow_plugins?, include_unofficial: allow_third_party_plugins?, request: request).each do |file| %>
       <%= preload_script file %>

app/views/qunit/theme.html.erb

@@ -9,7 +9,6 @@
       <%= preload_script "locales/en" %>
       <%= preload_script "vendor" %>
       <%= preload_script "discourse/tests/theme_qunit_vendor" %>
-      <%= preload_script "pretty-text-bundle" %>
       <%= preload_script "markdown-it-bundle" %>
       <%= preload_script "application" %>
       <%- Discourse.find_plugin_js_assets(include_official: allow_plugins?, include_unofficial: allow_third_party_plugins?, request: request).each do |file| %>

spec/requests/qunit_controller_spec.rb

@@ -100,7 +100,6 @@ describe QunitController do
         expect(response.body).to include("/assets/locales/en.js")
         expect(response.body).to include("/assets/vendor.js")
         expect(response.body).to include("/assets/discourse/tests/theme_qunit_vendor.js")
-        expect(response.body).to include("/assets/pretty-text-bundle.js")
         expect(response.body).to include("/assets/markdown-it-bundle.js")
         expect(response.body).to include("/assets/application.js")
         expect(response.body).to include("/assets/admin.js")