feat(api): add AppSync GraphQL APIs to the cloud explorer

Create GraphQL APIs with API-key (the first key is made for you), IAM or
Cognito user pool authorization, then edit the schema (a starter schema is
offered, and a rejected one is explained), create and delete API keys, create
data sources for a DynamoDB table, a Lambda function or none, and attach
JavaScript resolvers to fields of the schema from a template for the data
source.

TheCloud's endpoint checks queries against the schema and the API key but does
not run resolvers yet, so the page says so and offers no query runner.

packages/api/package.json

@@ -14,6 +14,7 @@
     "@aws-sdk/client-api-gateway": "^3.1076.0",
     "@aws-sdk/client-apigatewayv2": "^3.1076.0",
     "@aws-sdk/client-appconfig": "^3.1076.0",
+    "@aws-sdk/client-appsync": "^3.1146.0",
     "@aws-sdk/client-athena": "^3.1146.0",
     "@aws-sdk/client-auto-scaling": "^3.1146.0",
     "@aws-sdk/client-cloudformation": "^3.1111.0",