feat: allow persist runtime mode so that side effects of prior executions impact current one

[julianstephen]

Enable flag in gx.execute that will allow multiple invocations of code with the same interpreter runtime. Maintaining code state.

E.g.:

1. step1_result = g.execute(python_code).get_docker_result()
2. say python_code in step 1 here sets c=4
3. new_pthon_code= c+100
4. step2_result = g.execute(new_pthon_code).get_docker_result()

Expect step 4 to return 104

[julianstephen]

We can potentially create a _multi_executor.py along with current _executor.py

import multiprocessing

def worker(queue):
    while True:
        code = queue.get()
        if code == "STOP":
            break
        exec(code) # Executes code from other process

if __name__ == '__main__':
    queue = multiprocessing.Queue()
    p = multiprocessing.Process(target=worker, args=(queue,))
    p.start()
    
    # Send code from this process
    queue.put("print('Hello from Process 2')")
    queue.put("x = 10; print(f'Result: {x*2}')")
    queue.put("STOP")
    p.join()

In Guardx.execute(), we init the multi_executor, which will keep running in the worker while loop and we keep putting code to be executed into the queue.. Let me know what other think. @salmanyam @mvle

May have to create a polling service which will keep picking up files being copied into the container and keep giving it to the queue.