harden: key remembered site permissions by full origin (closes #402)

allowedSites and deniedSites held the bare hostname, so a grant to
https://dapp.example also authorised http://dapp.example and every port
on that host, and the connection, transaction and signature prompts
named only the hostname. Both lists now store and match the full origin
(scheme://host[:port]), the key the connections approved without
Remember already used. The prompts, the Settings site lists and
AUTISTMASK_REMOVE_SITE use the origin too. Entries saved by hostname
are not migrated (pre-1.0): they match no site.

Model: opus-5-5

tests/chainSwitchGate.test.js

@@ -19,7 +19,6 @@ const ADDRESS = "0x66133E8ea0f5D1d612D2502a968757D1048c214a";
 
 // The site the persisted state has connected, and one it has never heard of.
 const CONNECTED_ORIGIN = "https://dapp.example";
-const CONNECTED_HOSTNAME = "dapp.example";
 const STRANGER_ORIGIN = "https://stranger.example";
 
 const MAINNET = networkById("mainnet");
@@ -86,7 +85,7 @@ function loadBackground() {
         tokenHolderCache: {},
         fraudContracts: [],
         activeAddress: ADDRESS,
-        allowedSites: { [ADDRESS]: [CONNECTED_HOSTNAME] },
+        allowedSites: { [ADDRESS]: [CONNECTED_ORIGIN] },
         deniedSites: {},
     };
     const storage = makeStorageStub({ autistmask: persisted });