Replace 'wasm-pack' by 'trunk'

frontend/Trunk.toml

@@ -0,0 +1,12 @@
+[build]
+dist = "../backend/static/wasm"
+public_url = "/static"
+filehash = false
+minify = "on_release"
+
+# Here we don't want the file 'index.html' in the final directory.
+# Is there a way to not generate it at first?
+[[hooks]]
+stage = "post_build"
+command = "rm"
+command_arguments = ["../backend/static/wasm/.stage/index.html"]