Fix bin/webpack when ui-classic not bundled

When building rpms, we do not run bundle update in ui-classic (we only run in core)

To build the ui assets, we use `rake update:ui` which calls `./bin/webpack`.
The webpack command needs to know the i18n gem, and asks bundler for that path.
Since bundler has not been installed, this command fails.

The solution is to populate the i18n path in our paths.json file.
Since this path was known when we created paths.json, this is easier to do.

Before
======

So when running bin/webpack, we get an error when running `bundle info`:

```
./bin/webpack

Ruby versions >= 3.2.0 are untested!
The git source https://github.com/ManageIQ/amazon_ssa_support.git is not yet
checked out. Please run `bundle install` before trying to start your application
manageiq-ui-classic/node_modules/webpack-cli/bin/cli.js:93
				throw err;
```

After
=====

```
./bin/webpack

[success]
```

Author: kbrock

config/webpack/configuration.js

@@ -8,7 +8,7 @@ const { readFileSync } = require('fs');
 const configPath = resolve('config', 'webpacker.yml');
 const settings = safeLoad(readFileSync(configPath), 'utf8')[env.NODE_ENV];
 
-const { output: outputRoot, engines } = require('./paths.json');
+const { output: outputRoot, i18n, engines } = require('./paths.json');
 
 function removeOuterSlashes(string) {
   return string.replace(/^\/*/, '').replace(/\/*$/, '');
@@ -32,5 +32,6 @@ module.exports = {
   settings,
   env,
   output,
+  i18n,
   engines,
 };

config/webpack/shared.js

@@ -12,15 +12,15 @@ const DuplicatePackageCheckerPlugin = require('duplicate-package-checker-webpack
 const { SplitChunksPlugin } = require('webpack').optimize;
 const { execSync } = require('child_process');
 
-const { env, settings, output, engines } = require('./configuration.js');
+const { env, settings, i18n, output, engines } = require('./configuration.js');
 const loaders = require('./loaders.js');
 const RailsEnginesPlugin = require('./RailsEnginesPlugin');
 
 const extensionGlob = `**/*{${settings.extensions.join(',')}}*`; // */
 const entryPath = join(settings.source_path, settings.source_entry_path);
 const moduleDir = engines['manageiq-ui-classic'].node_modules;
 
-const gettextDir = execSync('bundle info --path gettext_i18n_rails_js', { encoding: 'utf-8' }).trim();
+const gettextDir = i18n;
 
 const sharedPackages = [
   '@carbon/icons-react',

lib/tasks/manageiq/ui_tasks.rake

@@ -66,9 +66,12 @@ namespace :webpack do
   end
 
   task :paths do
+    i18n_path = Bundler::CLI::Common.select_spec("gettext_i18n_rails_js").full_gem_path
+
     json = JSON.pretty_generate(
       :info    => "This file is autogenerated by rake webpack:paths, do not edit",
       :output  => Rails.root.to_s,
+      :i18n    => i18n_path,
       :engines => asset_engines.map { |p|
                     key = p.namespace
                     value = {:root => p.path,