Wrong default name of html log

[k-dovgan]

Currently when using the -hl option without any further specification the name of a created file is default (instead of expected universum_log.html).
Need to be expected, fixed and, maybe, covered by regression test

[dogbert911]

This issue is related to #703

[miltolstoy]

The current problem can be solved by #713, but a more general fix is needed to solve all similar situations (like #703).

Root issue - subparser arguments override main parser arguments with the same name:

./test.py --arg value1 subparser --arg value2
Namespace(arg='value2')

The current solution of the root issue - #715, appending the "default" parser.
But the current solution leads to issues like this one, so it should be done in some other way.

A preliminary investigation shows the possible way to resolve it.
Parser settings:

parser.add_argument("--arg", dest="main_arg")
subparser.add_argument("--arg", dest="subparser_arg")

Usage:

./test.py --arg value1 subparser --arg value2
Namespace(main_arg='value1', subparser_arg='value2')

Possible CLI help formatting issues can be resolved based on this StackOverflow information - https://stackoverflow.com/a/56595689