`auth_check_wrapper.cpp`: `strlen` usage is a bit wonky

[SwooshyCueb]

This line in auth_check_wrapper.cpp is of some concern: https://github.com/irods/irods_auth_plugin_pam_interactive/blob/f07902328fc4b686b2f79da152c8fb89f579696c/src/auth_check_wrapper.cpp#L16

• strlen is in the std:: namespace, so should be referred to as std::strlen.
• std::strlen comes from <cstring>, but <cstring> is never #included.
• std::strlen returns std::size_t, not uint32_t. It appears intentional that n is a uint32_t, so static_cast should be used.
• uint32_t is in the std:: namespace, so should be referred to as std::uint32_t.
• std::uint32_t comes from <cstdint>, but <cstdint> is never #included.

[korydraughn]

@SwooshyCueb Please close if completed.