fix(chains): strip every keyed provider URL, and make the gate fail closed

The first pass matched only `infura.io/.../v3/<lowercase hex>`, so it missed
`https://...infura.io/v3/<key>`, upper-case keys and hosts, and Nova's
OnFinality `?apikey=` URLs (Moonriver, and the Hades testnet in v20/v21
preConfigured). preConfigured was copied from Nova without the filter, and the
integrity check passed if grep itself failed.

- one predicate, is_keyed(), in sync_from_nova.py: Infura /v3/ ids and
  apikey/api_key/key/token query values, case-insensitive; {PLACEHOLDER}
  values are allowed
- preConfigured details are filtered after the copy; a chain left with no
  node loses its details file and its index entry (Hades, v20/v21 only)
- rewritten files keep their own indent, so the diff is the data change only
- check 5 imports is_keyed() and checks every string in every JSON file
  under chains/; an unreadable file or an empty tree is an error
- check 3 reports a grep error instead of passing on it

chains/v21/preConfigured/chains_dev.json

@@ -135,10 +135,6 @@
         "chainId": "65c489fb7bfaf4a27f283faf694a64a8d7ae8fc0ed970fc4ebbf25d03095e4d0",
         "name": "Niskala (TESTNET)"
     },
-    {
-        "chainId": "d9d12d9139d020f658d4469fa5c02e331195227da62567d7bf9bbd1abaf77522",
-        "name": "Parachain Hades testnet (TESTNET)"
-    },
     {
         "chainId": "466edf864b4314b97f36e45ec21ddb39e0bdc52789377b91be0957d5afad2eb2",
         "name": "Energy Web X Paseo (TESTNET)"