feat: add command line args for duckdb-server-rust

[kwonoh]

This PR adds a few command line arguments for duckdb-server-rust.
I used clap for parsing arguments.

I set the database path as positional argument following the Python server (duckdb-server).

I am new to Rust so please review this carefully :)

> ./duckdb-server --help                                       
DuckDB Server for Mosaic.

Usage: duckdb-server [OPTIONS] [DATABASE]

Arguments:
  [DATABASE]  Path of database file (e.g., "database.db". ":memory:" for in-memory database) [default: :memory:]

Options:
  -p, --port <PORT>                                  HTTP Port [default: 3000]
      --connection-pool-size <CONNECTION_POOL_SIZE>  Max connection pool size [default: 10]
      --cache-size <CACHE_SIZE>                      Max number of cache entries [default: 1000]
  -h, --help                                         Print help
  -V, --version                                      Print version

[domoritz]

thank you

[domoritz]

Released in 0.2 alongside some other improvements.