space optimizations for node_modules and client stats removal

- replace sharp with lighter jimp alternative
- remove stats in builds

fixes #2807

server/helpers/image-utils.ts

@@ -1,7 +1,7 @@
 import 'multer'
-import * as sharp from 'sharp'
 import { readFile, remove } from 'fs-extra'
 import { logger } from './logger'
+const Jimp = require('jimp')
 
 async function processImage (
   path: string,
@@ -10,20 +10,21 @@ async function processImage (
   keepOriginal = false
 ) {
   if (path === destination) {
-    throw new Error('Sharp needs an input path different that the output path.')
+    throw new Error('Jimp needs an input path different that the output path.')
   }
 
   logger.debug('Processing image %s to %s.', path, destination)
 
   // Avoid sharp cache
   const buf = await readFile(path)
-  const sharpInstance = sharp(buf)
+  const jimpInstance = await Jimp.read(buf)
 
   await remove(destination)
 
-  await sharpInstance
+  await jimpInstance
     .resize(newSize.width, newSize.height)
-    .toFile(destination)
+    .quality(80)
+    .writeAsync(destination)
 
   if (keepOriginal !== true) await remove(path)
 }