reorganized the code

[iaacornus]

• The spinner in download function were put back again, since it does not cause any error. During my testing before putting the spinner, the program is already returning only 143 or only 140's episode, not 300+, so I think it is rather a source problem. But I still didn't touched the Play function, only the download function.
• The code were also reorganized, the one prominent changes made is the function were passed onto each other instead of putting the returned value to another variable that will be used by another function. So instead of this :

...
source = VideoSource(episodes[x+1])
Download(source)
print(f"Episode {x+1} downloaded!", end="")
...

This was done instead :

...
Download(VideoSource(episodes[x+1]))
...

• raise SystemExit(ERROR_MESSAGE) was also used instead of :

...
print(ERROR_MESSAGE)
sys.exit()
...

since this one is more efficient.

• Duplicates of except KeyboardInterrupt were also removed.
• the output of subprocess calling youtube-dl were also redirected back into subprocess.DEVNULL and its STDERROR were also redirected back into subprocess.STDOUT
• else block were also used instead of try/except in some cases.
• Also, instead of specifying the number of episodes in list function, len(episodes) were used instead to avoid error.

[iaacornus]

I limited the use of other functions to optimize the memory usage of the application, I also removed duplication as much as I can.

It is also good to note that I also called os.system("clear") and the list function every continue or repeat in while True block, since the program is under verbose mode especially the Play function.

[trakBan]

Thanks for contributing to spongebob-cli. Approved