File should accept both string and pathlib.Path

[erikfrojdh]

from pathlib import Path

fpath = Path('/Users/erik/data/cluster/cu_half_speed_master_4.json')
f = File(fpath, 'r')

results in:

Traceback (most recent call last):
  File "/Users/erik/software/aare/src/python/example/scratch.py", line 6, in <module>
    f = File(fpath, 'r')
        ^^^^^^^^^^^^^^^^
TypeError: __init__(): incompatible constructor arguments. The following argument types are supported:
    1. _aare.File(arg0: _aare.Path)
    2. _aare.File(arg0: _aare.Path, arg1: str)
    3. _aare.File(arg0: _aare.Path, arg1: str, arg2: aare::FileConfig)

Invoked with: PosixPath('/Users/erik/data/cluster/cu_half_speed_master_4.json'), 'r'

Current workaround

f = File(fpath.as_posix(), 'r')