fix: Add fix and test for 'triton' with no args

[rmccorm4]

Before:

$ triton
triton - ERROR - list index out of range
triton - ERROR - Unexpected error:
Traceback (most recent call last):
  File "/usr/local/lib/python3.10/dist-packages/triton_cli/main.py", line 51, in main
    run()
  File "/usr/local/lib/python3.10/dist-packages/triton_cli/main.py", line 44, in run
    args = parser.parse_args(argv)
  File "/usr/local/lib/python3.10/dist-packages/triton_cli/parser.py", line 447, in parse_args
    if argv_[0] == "profile":
IndexError: list index out of range

After:

$ triton
usage: triton [-h] [-v] {import,remove,list,start,infer,profile,metrics,config,status} ...
triton: error: the following arguments are required: {import,remove,list,start,infer,profile,metrics,config,status}

[KrishnanPrash]

I have a general workflow question:
Do we want to error out for someone using the triton command without any args? What are the cons of something like this?

/opt/tritonserver# triton
usage: triton [-h] [-v]
              {import,remove,list,start,infer,profile,metrics,config,status} ...
triton: For further information, ex: triton import -h
/opt/tritonserver# echo $?
0

[rmccorm4]

Can you clarify the question? Are you asking if we care whether the return code is 0 or 2 for running triton with no args? If so, I don't think it's a big deal either way as long as the help message is output to the screen. I defaulted to letting argparse use its default behavior, which happened to be return code 2. It's a sign to the user they're doing something wrong and need an arg, but a convenience for people too lazy to type -h/--help

[KrishnanPrash]

Can you clarify the question? Are you asking if we care whether the return code is 0 or 2 for running triton with no args? If so, I don't think it's a big deal either way as long as the help message is output to the screen. I defaulted to letting argparse use its default behavior, which happened to be return code 2. It's a sign to the user they're doing something wrong and need an arg, but a convenience for people too lazy to type -h/--help

Yup, I was primarily wondering if we want to consider the no args command triton an error and depending on that if we want to provide return code of 0 or 2.

[KrishnanPrash]

Overall looks good to me! With this the error message should be much more helpful than the previous unrelated profile error.