Add token revocation mechanism and support for logout APIs

This commit introduces a system to revoke tokens by storing their `jti` in a new `RevokedToken` model. It includes APIs for logging out (revoking a current token) and logging out from all devices (revoking all tokens). Additionally, token validation now checks revocation status during the decode process.

backend/app/models/user.py

@@ -25,6 +25,7 @@ class User(Base, UUIDMixin, TimestampMixin):
         foreign_keys="EventManager.user_id"
     )
     guest_profiles = relationship("Guest", back_populates="user", foreign_keys="Guest.user_id")
+    revoked_tokens = relationship("RevokedToken", back_populates="user", cascade="all, delete")
 
     def __repr__(self):
         return f"<User {self.email}>"