[Fixes#38426061, #38097411]
Msf::Modules::Loader::Directory#read_module_content may calculate a non-existent
module_path that gets passed to File.open causing an Errno::ENOENT exception
to be raised when using the module cache with a module that has been
moved to a new path (as is the case that originally found this bug) or
deleted. Now, the exception is rescued and read_module_content returns
an empty string (''), which load_module detects with
module_content.empty? and returns earlier without attempting to module
eval the (empty) content.
As having Msf::Modules::Loader::Directory#read_module_content rescue the
exception, meant there was another place that needed to log and error
and store an error in Msf::ModuleManager#module_load_error_by_path, I
refactored the error reporting to call
Msf::Modules::Loader::Base#load_error, which handles writing to the log
and setting the Hash, so the error reporting is consistent across the
loaders.
The exception hierarchy was also refactored so that
namespace_module.metasploit_class now has an error raising counter-part:
namespace_module.metasploit_class! that can be used with
Msf::Modules::Loader::Base#load_error as it requires an exception, and
not just a string so the exception class, message, and backtrace can be
logged.