Add special "0x0" chainID for universally supported capabilities

EIPS/eip-5792.md

@@ -278,6 +278,7 @@ If any of these supplemental expressions of capabilities are contradicted by cap
 
 Capabilities are returned in key/value pairs, with the key naming a capability and a value conforming to a shape defined for that name, in an object keyed to the relevant [EIP-155](./eip-155.md) `chainId` expressed in hexadecimal notation.
 Capabilities are nested in per-chain objects because wallets may support different capabilities across multiple chains authorized in a given session.
+Capabilities that the wallet supports on all the chains SHOULD be included only once, using a special `chainID` value `"0x0"`, and SHOULD NOT be repeated in nested per-chain objects.
 
 ```typescript
 type GetCapabilitiesParams = [`0x${string}`, [`0x${string}`]]; // Wallet address, array of queried chain ids (optional)
@@ -297,6 +298,11 @@ The capabilities below are for illustrative purposes.
 
 ```json
 {
+  "0x0": {
+    "flow-control": {
+      "supported": true
+    }
+  },
   "0x2105": {
     "paymasterService": {
       "supported": true
@@ -306,7 +312,7 @@ The capabilities below are for illustrative purposes.
     }
   },
   "0x14A34": {
-    "paymasterService": {
+    "auxiliaryFunds": {
       "supported": true
     }
   }