[feat][Remote objects] Edit a connection (for pg) (#5210)

## Context
#4774 

## How was it tested
Locally

## In further PRs
- Update connection status upon page change
- Adapt Info banner to dark mode
- placeholders for form

packages/twenty-front/src/modules/databases/graphql/fragments/databaseConnectionFragment.ts

@@ -7,6 +7,10 @@ export const DATABASE_CONNECTION_FRAGMENT = gql`
     foreignDataWrapperId
     foreignDataWrapperOptions
     foreignDataWrapperType
+    userMappingOptions {
+      username
+    }
     updatedAt
+    schema
   }
 `;