YT-CPPAP-61: Add subparsers support

[SpectraL519]

• Extended the argument_parser class with members and functions allowing users to manage subparsers
• Aligned the argument parsing functionality:
  • A parser tries to match the first argument from its input argument range to a subparser
  • If a match is found, the corresponding subparser is invoked with the remaining arguments
  • If no match is found, the current parser finalizes parsing arguments
• Aligned the argument parsing functionality to allow forward ranges only
• Added the name and program_name attribute accessor functions in argument_parser
• Restricted the creation of positional arguments to using only one argument name
• Added the possibility to bind positional arguments to argument groups
• Added an is_used(arg_name) method for checking the usage status of an argument
• Added an o_version default argument which prints the parser's version info
• Renamed the argument_descriptor class to help_builder
• Fixed an error where the requirements of all arguments within a mutually exclusive group were verified, which caused unexpected exceptions
• Added the logging_mode and ap_git demo projects

[SpectraL519]

TODO:

• Bump project version
• An argument group demo project
• The ap-git demo project
• Add a list of demo projects in the tutorial page

[SpectraL519]

ok