DEV: Rename 'bootstrap-json' addon to 'custom-proxy' (#26561)

It was originally named bootstrap-json because it contacted a 'bootstrap' API in rails to generate the ember-cli html response. However, it has since been overhauled to remove that 'bootstrap' system. Now it is a much simpler proxy server which transforms the HTML sent by Rails.

app/assets/javascripts/custom-proxy/package.json

@@ -1,5 +1,5 @@
 {
-  "name": "bootstrap-json",
+  "name": "custom-proxy",
   "version": "1.0.0",
   "description": "Express.js middleware which injects ember-cli asset URLs into Discourse's HTML",
   "author": "Discourse",

app/assets/javascripts/discourse/package.json

@@ -65,7 +65,7 @@
     "babel-import-util": "^2.0.1",
     "babel-plugin-ember-template-compilation": "^2.2.1",
     "bootstrap": "3.4.1",
-    "bootstrap-json": "1.0.0",
+    "custom-proxy": "1.0.0",
     "broccoli-asset-rev": "^3.0.0",
     "deepmerge": "^4.3.1",
     "deprecation-silencer": "1.0.0",

package.json

@@ -59,7 +59,7 @@
   },
   "workspaces": [
     "app/assets/javascripts/admin",
-    "app/assets/javascripts/bootstrap-json",
+    "app/assets/javascripts/custom-proxy",
     "app/assets/javascripts/deprecation-silencer",
     "app/assets/javascripts/dialog-holder",
     "app/assets/javascripts/discourse",