fix bug: AttributeError: 'Namespace' object has no attribute 'localfile' for fetch command

[huakim]

No description provided.

[mcepl]

Also, please, add more to the description of this PR: I really don’t know what error it actually fixes (traceback? reproducer?) and thus I really don’t understand and cannot review how this commits helps.

[huakim]

Also, please, add more to the description of this PR: I really don’t know what error it actually fixes (traceback? reproducer?) and thus I really don’t understand and cannot review how this commits helps.

Steps to reproduce:

• 1: write 'py2pack fetch py2pack' to command line
  Expected result:
  py2pack tarball is downloaded
  Current result:
  traceback (most recent call):
  AttributeError: 'Namespace' object has no attribute 'localfile' for fetch command

The reason:
the object of Argparser class does not have local and localfile attributes, if we type 'py2pack fetch'
i added workaround with try - except, but, later, workaround was deleted
then i added one function 'fetch_local_data', which will work with attributes local and localfile, if none of these flags are provided, then 'fetch_local_data' function will call 'fetch_data' function

[mcepl]

Looks to me all right now.

[mcepl]

Please, rebase.

[huakim]

Please, rebase.

i added new branch 'main'