Add the tests for the extensions pg_jsonschema and pg_session_jwt (#11323)

## Problem
`pg_jsonschema` and `pg_session_jwt` are not yet covered by tests
## Summary of changes
Added the tests for these extensions.

docker-compose/ext-src/pg_jsonschema-src/sql/jsonschema_valid_api.sql

@@ -0,0 +1,48 @@
+-- Define schema
+SELECT jsonschema_is_valid('{
+  "type": "object",
+  "properties": {
+    "username": { "type": "string" },
+    "age": { "type": "integer" }
+  },
+  "required": ["username"]
+}'::json);
+
+-- Valid instance
+SELECT jsonschema_validation_errors(
+  '{
+    "type": "object",
+    "properties": {
+      "username": { "type": "string" },
+      "age": { "type": "integer" }
+    },
+    "required": ["username"]
+  }'::json,
+  '{"username": "alice", "age": 25}'::json
+);
+
+-- Invalid instance: missing required "username"
+SELECT jsonschema_validation_errors(
+  '{
+    "type": "object",
+    "properties": {
+      "username": { "type": "string" },
+      "age": { "type": "integer" }
+    },
+    "required": ["username"]
+  }'::json,
+  '{"age": 25}'::json
+);
+
+-- Invalid instance: wrong type for "age"
+SELECT jsonschema_validation_errors(
+  '{
+    "type": "object",
+    "properties": {
+      "username": { "type": "string" },
+      "age": { "type": "integer" }
+    },
+    "required": ["username"]
+  }'::json,
+  '{"username": "bob", "age": "twenty"}'::json
+);