frontend: Don't copy resources to language dirs

Since 355e89ce5, the frontend references resources via root-relative URLs.
This means that `resources` dirs in the language dirs are no longer
accessed and can be removed.

Achieve this by defining a specific `assets` production config that
doesn't include `src/resources`.

As of fd35c8f4a, this shrinks the frontend size by 55% (279M -> 124M).

Also, the nginx location configs now can be simplified.

frontend/angular.json

@@ -170,6 +170,10 @@
           },
           "configurations": {
             "production": {
+              "assets": [
+                "src/favicon.ico",
+                "src/robots.txt"
+              ],
               "fileReplacements": [
                 {
                   "replace": "src/environments/environment.ts",

frontend/package.json

@@ -34,7 +34,7 @@
     "start:local-staging": "npm run generate-config && npm run sync-assets-dev && npm run ng -- serve -c local-staging",
     "start:mixed": "npm run generate-config && npm run sync-assets-dev && npm run ng -- serve -c mixed",
     "build": "npm run generate-config && npm run ng -- build --configuration production --localize && npm run sync-assets && npm run build-mempool.js",
-    "sync-assets": "node sync-assets.js && rsync -av ./dist/mempool/browser/en-US/resources ./dist/mempool/browser/resources",
+    "sync-assets": "rsync -av ./src/resources ./dist/mempool/browser && node sync-assets.js",
     "sync-assets-dev": "node sync-assets.js dev",
     "generate-config": "node generate-config.js",
     "build-mempool.js": "npm run build-mempool-js && npm run build-mempool-liquid-js && npm run build-mempool-bisq-js",

frontend/sync-assets.js

@@ -4,7 +4,7 @@ var fs = require('fs');
 const CONFIG_FILE_NAME = 'mempool-frontend-config.json';
 let configContent = {};
 
-var PATH = 'dist/mempool/browser/en-US/resources/';
+var PATH = 'dist/mempool/browser/resources/';
 if (process.argv[2] && process.argv[2] === 'dev') {
   PATH = 'src/resources/';
 }