[Frontend] Add SECRET credential type for storing generic sensitive values (#4258)

skyvern-frontend/src/routes/workflows/components/CredentialSelector.tsx

@@ -62,7 +62,9 @@ function CredentialSelector({ value, onChange }: Props) {
                 <p className="text-xs text-slate-400">
                   {credential.credential_type === "password"
                     ? "Password"
-                    : "Credit Card"}
+                    : credential.credential_type === "credit_card"
+                      ? "Credit Card"
+                      : "Secret"}
                 </p>
               </div>
             </CustomSelectItem>

skyvern-frontend/src/routes/workflows/editor/nodes/HttpRequestNode/HttpRequestNode.tsx

@@ -399,9 +399,10 @@ function HttpRequestNode({ id, data }: NodeProps<HttpRequestNodeType>) {
                 authentication and content headers
               </li>
               <li>
-                Pass a credential/secret parameter and reference it in headers
-                or body with {"{{ my_credential.password }}"}
+                Password credential: {"{{ my_credential.username }}"} /{" "}
+                {"{{ my_credential.password }}"}
               </li>
+              <li>Secret credential: {"{{ my_secret.secret_value }}"}</li>
               <li>
                 The request will return response data including status, headers,
                 and body