Adding EdDSA support for io.jwt built-ins (#7824)

Introducing the `io.jwt.verify_eddsa` built-in, and adding support to the following built-ins:

* `io.jwt.decode_verify`
* `io.jwt.encode_sign`
* `io.jwt.encode_sign_raw`

Signed-off-by: Johan Fylling <johan.dev@fylling.se>

capabilities.json

@@ -1814,6 +1814,23 @@
       },
       "nondeterministic": true
     },
+    {
+      "name": "io.jwt.verify_eddsa",
+      "decl": {
+        "args": [
+          {
+            "type": "string"
+          },
+          {
+            "type": "string"
+          }
+        ],
+        "result": {
+          "type": "boolean"
+        },
+        "type": "function"
+      }
+    },
     {
       "name": "io.jwt.verify_es256",
       "decl": {