feat: Implement log endpoint

[motionduck]

This pull request introduces a new API endpoint for logging messages from a client to new a database table called log_client, while the server log table has been renamed to log_server. It also adds validation, error handling, and comprehensive tests for the new logging functionality.

API and Logging Functionality

• Added a new POST /api/log endpoint that allows authenticated clients to send log messages to the server, with validation for message content and log level.
  • The request body requires a message property, which can be any string up to 1000 characters.
  • Optionally, a client can provide a level property, which can be any of the following strings: "alert", "error", "warn", "info", "fail", "success", "log", "debug", or"verbose". If not provided, the log will default to log level "info".
  • Optionally, a client can provide a timestamp property, which if not provided will default to the current time.
  • Each log entry will be saved alongside the request's user ID, session ID, and IP address.

Database Schema and Logging Procedure

• Added a new table log_client, while renaming the old log table to log_server.
• Split the log_to_db SQL function into two separate functions log_server_to_db and log_client_to_db.

Testing and Documentation

• Added integration tests for the new logging endpoint, covering validation, error handling, and successful log insertion scenarios. (server/tests/log.test.ts)
• Updated the OpenAPI documentation to include the new endpoint, as well as another older endpoint that was not yet documented.

Closes #431