command "lsl" throws an error

[LucasBornhauser]

Describe the bug
When running
"./docxbox lsl filename.docx {missing search string}"
or
"./docxbox lsl {missing filename}"
an error is thrown:
terminate called after throwing an instance of 'std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >'

To Reproduce
Steps to reproduce the behavior:

1. Command :

• ./docxbox lsl table_unordered_list_images.docx

OR

• ./docxbox lsl

2. Resources: table_unordered_list_images.docx

Expected behavior
An error message stating that a required argument is missing respectively
An error message stating that a required file is missing

Environment:

• docxBox Version: 0.0.4