feat(auth): Enhance Google OAuth service with CSRF protection and validation logic

feat(auth): Add error handling for authentication and validation errors
feat(auth): Implement default role assignment for new users in Google OAuth flow
feat(utils): Introduce CSRF token generation and validation utilities
fix(dependencies): Update Cargo.toml to include base64 and sha2 dependencies

imphnen-utils/Cargo.toml

@@ -19,5 +19,7 @@ strum.workspace = true
 strum_macros.workspace = true
 uuid.workspace = true
 tracing.workspace = true
+base64.workspace = true
+sha2.workspace = true
 dotenvy = { workspace = true }
 tracing-subscriber = { workspace = true, features = ["env-filter"] }