Deduplicate syncUser and syncGroup logic in KeycloakAdminService

[coderabbitai]

Description

The syncUser and syncGroup methods in KeycloakAdminService duplicate logic from KeycloakAuthorityPuller. Both synchronization methods should share the same implementation to maintain consistency.

Affected Code

• syncUser method (line ~183 in KeycloakAdminService.java)
• syncGroup method (line ~214 in KeycloakAdminService.java)

Both methods have TODO comments indicating the need for deduplication with KeycloakAuthorityPuller.

Related PR

• PR: Add user and group management UI #376
• Review Comment: Add user and group management UI #376 (comment)

Requested by

@overheadhunter