load_file operator silently fails if the local file is not existing

[utkarsharma2]

Describe the bug
When we use the load_file operator and pass a local file and the file doesn't exist, the operator does nothing and fails silently.

Version

• Astro: [e.g. 0.9.2]

To Reproduce
Steps to reproduce the behavior:

1. Use the load_file operator:

    aql.load_file(  # noqa: F841
           input_file=File(
               path='/tmp/non_existing_file.csv',
           ),
           task_id="load_csv",
           output_table=table_metadata,
           chunk_size=chunk_size,
    )
   

2. Now the operator will run without any warning or failure making the user think that the operator ran successfully.

Expected behavior
Case 1 (default)

The operator should fail with an error if param if_file_doesnt_exist is set to exception saying that the file doesn't exist.

Case 2

if the if_file_doesnt_exist is set to suppress the operator should not raise an exception.

To accommodate this behaviour added a parameter if_file_doesnt_exist to load_file() operator and get_file() function.

[kaxil]

@utkarsharma2 this can be closed, right?

can you comment which PR closed it plz

[kaxil]

closed by #476