This commit updates the configuration settings and improves the notification functionality by filtering out duplicate notifications. It also includes changes to feature flag data types and removed dependencies in `package.json`, alongside updates to `pnpm-lock.yaml`.
Several updates are made to the notification model, mainly removing the 'entity_id', 'entity_type', and 'language_code' fields from the properties. We've also updated the 'accounts_memberships' table, by preventing its updates except for 'account_role'.
This update includes creating new files for the notifications feature along with adding two feature flags for enabling notifications and realtime notifications. All the code and package dependencies required for the notifications functionality have been added. The 'pnpm-lock.yaml' has also been updated due to the inclusion of new package dependencies.
