Deprecate implicit/magic import of irods_types or irods_errors

[SwooshyCueb]

In multiple places in main.cpp, we import irods_types and irods_errors and then stuff them into an already-imported module's __dict__, with the intention of making them available in the imported module:

irods_rule_engine_plugin_python/src/main.cpp

Lines 556 to 562 in 0f5df8f

	bp::object core_module = bp::import("core");
	bp::object core_namespace = core_module.attr("__dict__");
	bp::object irods_types = bp::import("irods_types");
	bp::object irods_errors = bp::import("irods_errors");
	core_namespace["irods_types"] = irods_types;
	core_namespace["irods_errors"] = irods_errors;

irods_rule_engine_plugin_python/src/main.cpp

Lines 717 to 727 in 0f5df8f

	bp::object main_module = bp::import("__main__");
	bp::object main_namespace = main_module.attr("__dict__");
	bp::object irods_types = bp::import("irods_types");
	bp::object irods_errors = bp::import("irods_errors");
	// Import global INPUT and OUTPUT variables
	main_namespace["global_vars"] = global_vars_python;
	// Import global constants
	main_namespace["irods_types"] = irods_types;
	main_namespace["irods_errors"] = irods_errors;

irods_rule_engine_plugin_python/src/main.cpp

Lines 851 to 861 in 0f5df8f

	bp::object main_module = bp::import("__main__");
	bp::object irods_types = bp::import("irods_types");
	bp::object irods_errors = bp::import("irods_errors");
	bp::object main_namespace = main_module.attr("__dict__");
	// Import global INPUT and OUTPUT variables
	main_namespace["global_vars"] = global_vars_python;
	// Import globals
	main_namespace["irods_types"] = irods_types;
	main_namespace["irods_errors"] = irods_errors;

This is bad for a few reasons:

• Modules are interpreted on import, before __dict__ can be changed by the C++ code doing the importing. Therefore, the modules are actually not available to any code executed on import.
• Changing __dict__ of a module in this manner creates further inconsistency for when these modules are implicitly available and when they must first be imported.
• import irods_types and import irods_errors work just fine. Users should be doing this instead of assuming they will already be imported. No magic pls.

Given that this would be a breaking change, we should first deprecate implicitly/magically imported irods_types and irods_errors before actually making the change.