Remove the local fork

"Fork Locally" ran the selected chain in the browser through
@acala-network/chopsticks-core, which brings its own @polkadot stack
(types, rpc-provider, util-crypto 13 and 14) and @polkadot/wasm-crypto
7.5.4 with the crate versions pezkuwi-wasm 7.5.21 moved off. The app
shipped that second wasm twice, next to ours, for a developer tool;
chopsticks itself stays available from the command line.

Gone: the button, the overlay, the "Local" mock-account modal and the
chopsticks account group, the fork path in the API context, and their
69 locale strings. Mock accounts a fork left in a browser's keyring are
address-only; they now show with the test accounts.

yarn.lock: 32 @polkadot and 2 @acala-network entries -> 0.

packages/apps/package.json

@@ -16,7 +16,6 @@
   "type": "module",
   "version": "1.0.2-1-x",
   "dependencies": {
-    "@acala-network/chopsticks-core": "^1.2.1",
     "@pezkuwi/apps-config": "^1.0.2-1-x",
     "@pezkuwi/apps-routing": "^1.0.2-1-x",
     "@pezkuwi/dev": "^0.86.8",