Fix bugs in `ligo publish`

changelog/2423

src/bin/expect_tests/package_management.ml

src/bin/publish.ml

src/main/helpers/ligo_ignore.ml

.../projects/publish_contract_slash_in_pkg_name/errors.mligo

...st/projects/publish_contract_slash_in_pkg_name/main.mligo

.../projects/publish_contract_slash_in_pkg_name/package.json

...est/projects/test_ligoignore_with_empty_lines/.ligoignore

...st/projects/test_ligoignore_with_empty_lines/errors.mligo

...ects/test_ligoignore_with_empty_lines/foo/dummy_lib.mligo

...t/projects/test_ligoignore_with_empty_lines/foo/lib.mligo

...test/projects/test_ligoignore_with_empty_lines/main.mligo

...st/projects/test_ligoignore_with_empty_lines/package.json