Add max_memory_usage field to tidesdb_config_t

[mukesh-2096]

Description

This PR adds the max_memory_usage configuration field to tidesdb_config_t, allowing users to set memory usage limits when opening a TidesDB database instance.

Changes Made

• Added size_t max_memory_usage field to the tidesdb_config_t FFI structure
• Updated tidesdb.default_config() to include max_memory_usage with a default value of 0 (unlimited)
• Modified TidesDB.new() constructor to handle the max_memory_usage configuration parameter
• Updated TidesDB.open() method to accept max_memory_usage as an option
• Default value of 0 indicates unlimited memory usage

Usage Example

local tidesdb = require("tidesdb")

-- Option 1: Using TidesDB.open() with max_memory_usage
local db = tidesdb.TidesDB.open("./mydb", {
    max_memory_usage = 512 * 1024 * 1024  -- 512 MB limit
})

-- Option 2: Using default config
local config = tidesdb.default_config()
config.max_memory_usage = 1024 * 1024 * 1024  -- 1 GB limit
local db = tidesdb.TidesDB.new(config)

[guycipher]

That's correct. Good stuff, thank you

[guycipher]

@mukesh-2096 one favor, can you put your new tests in test_tidesdb.lua, to be consistent. I do not like the new file, its random. Please follow the comment and code style.

[mukesh-2096]

@guycipher
okay, sure
i will update it

[guycipher]

Thank you