Remove shared_ptr from Python API

AFAIK the only way to add a Python module to PluginPlay is via a pattern like:

# Redundant import is issue
from pluginplay import pluginplay
from cppyy.gbl.std import make_shared

class MyModule(pluginplay.ModuleBase):
    def __init__(self):
        super().__init__(self)
        # rest of ctor

    
    def run_(self, inputs, submods):
        # rest of body

mm = pluginplay.ModuleManager()
mm.add_module("module key", make_shared[MyModule]())

# Ideal solution
# (currently doesn't work see #269)
# mm.add_module("module key", MyModule())

#Also fine 
#(currently doesn't work leads to double free or corruption error)
# mm.add_module[MyModule]("module key")

# Alternatively could expose a Python free function to wrap
# calling shared_ptr from Python, e.g.
#pluginplay.add_module(mm, MyModule)
#

Relying on std::shared_ptr is very non-Pythonic and I would suspect users would prefer one of the three suggestions over dealing with std::shared_ptr

Start by reviewing the Python binding entry points for ModuleBase and ModuleManager.add_module, then read the referenced issue #269 and compare the three proposed calling patterns. Done means a Python module can be registered without users explicitly constructing std::shared_ptr, while avoiding the reported double-free or corruption failure.