Accept pathlib.Path in loaders and dumpers

[multimeric]

What is your feature request?
The loaders and dumpers don't seem to understand pathlike types other than strings.

from linkml_runtime.loaders import JSONLoader
from pathlib import Path
JSONLoader().load(Path("example.json"), dict)

You get:

TypeError: object of type 'PosixPath' has no len()

Full traceback:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/migwell/Programming/json-ld-test/.venv/lib/python3.12/site-packages/linkml_runtime/loaders/loader_root.py", line 76, in load
    results = self.load_any(*args, **kwargs)
              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/migwell/Programming/json-ld-test/.venv/lib/python3.12/site-packages/linkml_runtime/loaders/json_loader.py", line 32, in load_any
    data_as_dict = self.load_as_dict(source, base_dir=base_dir, metadata=metadata)
                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/migwell/Programming/json-ld-test/.venv/lib/python3.12/site-packages/linkml_runtime/loaders/json_loader.py", line 21, in load_as_dict
    data = self._read_source(source, base_dir=base_dir, metadata=metadata, accept_header="application/ld+json, application/json, text/json")
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/migwell/Programming/json-ld-test/.venv/lib/python3.12/site-packages/linkml_runtime/loaders/loader_root.py", line 167, in _read_source
    data = hbread(source, metadata, base_dir, accept_header)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/migwell/Programming/json-ld-test/.venv/lib/python3.12/site-packages/hbreader/__init__.py", line 258, in hbread
    open_info.source_file_size = len(source)
                                 ^^^^^^^^^^^
TypeError: object of type 'PosixPath' has no len()

How important is this feature to you? Select from the options below:
Low

Additional context
I believe the best practice way to do this is not to add a special case for Path, but rather to accept str, bytes or os.PathLike as described here: https://docs.python.org/3/glossary.html#term-path-like-object.

[dalito]

The traceback is from an external lib that is not accepting Pathlib objects which was already reported there a while ago: hsolbrig/hbreader#11 - Since it hasn't been fixed yet, LinkML would better convert to str before calling hbreader.

On your additional context: When interfacing external code, being tolerant on how the path is received/passed is good. However, within LinkML the consistent use of Pathlib objects is helpful to detect problems and from what I observe it is gradually going into that direction.

[sierra-moxon]

linkml/linkml-runtime#354