Add a schemaExists check

The schemaExists check doesn't need `CREATE ON DATABASE` permissions. 

So it avoids throwing an error in case where both: 
- The schema already exists
- The user doesn't have  `CREATE ON DATABASE` permission

packages/nocodb/src/lib/db/sql-client/lib/pg/PgClient.ts

@@ -474,17 +474,22 @@ class PGClient extends KnexClient {
         ]);
       }
 
-      // if (this.connectionConfig.searchPath && this.connectionConfig.searchPath[0]) {
+      const schemaName = this.connectionConfig.searchPath?.[0] || 'public'
-      await this.sqlClient.raw(
+
-        ` CREATE SCHEMA IF NOT EXISTS ??  AUTHORIZATION ?? `,
+      // Check schemaExists because `CREATE SCHEMA IF NOT EXISTS` requires permissions of `CREATE ON DATABASE`
-        [
+      const schemaExists = !!(
-          (this.connectionConfig.searchPath &&
+        await this.sqlClient.raw(
-            this.connectionConfig.searchPath[0]) ||
+          `SELECT schema_name FROM information_schema.schemata WHERE schema_name = ?`,
-            'public',
+          [schemaName]
-          this.connectionConfig.connection.user,
+        )
-        ]
+      ).rows?.[0];
-      );
+
-      // }
+      if(!schemaExists) {
+        await this.sqlClient.raw(
+          `CREATE SCHEMA IF NOT EXISTS ??  AUTHORIZATION ?? `,
+          [schemaName, this.connectionConfig.connection.user]
+        );
+      }
 
       // this.sqlClient = knex(this.connectionConfig);
     } catch (e) {