Add function build_arg_list for building arguments list from keyword dictionaries

[seisman]

This PR contains the changes of commit 1149b37 in PR #3132.

In this PR, a new utility function build_arg_list function is added. The new function is modified from the build_arg_string function and it differs from the build_arg_string function in the following aspects:

1. returns a list of arguments, instead of a single argument string
2. no hacky solutions for handling whitespaces
3. Only apply the non_ascii_to_octal function to the single-letter option arguments, not to the configuration arguments and input/output files
4. Doctests are also simplified.

The goal is to replace build_arg_string with build_arg_list in all module wrappers and deprecate/remove build_arg_string in future releases.

PR #3132 contains more changes that we will apply after this PR is merged.

[weiji14]

Code logic ok, just some suggestions related to the type hints.