Add public metadata to Users and Clients

[dborovcanin]

Add public metadata to Users and Clients so it can be shared with other users safely.

We should have both public and private metadata.

1. Public metadata can contains non-sensitive user information that can be safely exposed to other users. Examples include a profile photo, language preferences, or theme settings.
2. Private metadata should sensitive or personally identifiable information that must be protected and only accessible internally. Examples include a user’s address, phone number, etc.

Separating public and private metadata is important because:

• prevents sensitive user information from being unintentionally exposed and reduces the risk of data leaks.

• allows safe sharing of public data while keeping private data restricted, which simplifies user access control and strengthens user trust.

Originally posted by @dborovcanin in #963

[felixgateru]

Updating estimate from 3 to 4 hrs to account to tests refactoring and testing