Add pathway entity

[Zethson]

• enrichr -> https://pfocr.wikipathways.org/
  I didn't really find any owl file that we could directly download. Maybe take the pathway names from http://download.baderlab.org/EM_Genesets/current_release/ (got there from https://enrichmentmap.readthedocs.io/en/latest/GeneSets.html)
• wikipathways -> https://www.wikipathways.org/
  Similar story to enrichr -> download from https://wikipathways-data.wmcloud.org/current/gmt/
• KEGG?
• ConsensusPathDB http://cpdb.molgen.mpg.de/
• GO terms
• Pathway ontology (https://www.ebi.ac.uk/ols/ontologies/pw) -> breaks with

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/zeth/miniconda3/envs/bionty/lib/python3.10/site-packages/cached_property.py", line 36, in __get__
    value = obj.__dict__[self.func.__name__] = self.func(obj)
  File "/home/zeth/PycharmProjects/bionty/bionty/_entity.py", line 121, in df
    df = self._ontology_to_df(self.ontology)
  File "/home/zeth/miniconda3/envs/bionty/lib/python3.10/site-packages/cached_property.py", line 36, in __get__
    value = obj.__dict__[self.func.__name__] = self.func(obj)
  File "/home/zeth/PycharmProjects/bionty/bionty/_entity.py", line 102, in ontology
    return Ontology(handle=localpath, **kwargs)
  File "/home/zeth/PycharmProjects/bionty/bionty/_ontology.py", line 32, in __init__
    super().__init__(
  File "/home/zeth/miniconda3/envs/bionty/lib/python3.10/site-packages/pronto/ontology.py", line 283, in __init__
    cls(self).parse_from(_handle)  # type: ignore
  File "/home/zeth/miniconda3/envs/bionty/lib/python3.10/site-packages/pronto/parsers/obo.py", line 45, in parse_from
    raise SyntaxError(s.args[0], location) from None
  File "/home/zeth/PycharmProjects/bionty/bionty/_dynamic/human_pw_7.74_Pathway___download?apikey=8b5b7825-538d-40e0-9e9e-5ab9274a9aeb", line 98
    def: "Those metabolic reactions involved in the synthesis, utilization and/or degradation of the primary or standard 20 amino acids found in proteins. Amino acids are described as non-essential or essential depending on whether humans can or can not synthesize them, respectively. Chemically, they are classified based on the polarity of their side chain or R group, as non-polar and hydrophobic and hydrophilic and charged or polar uncharged. Amino acid metabolic pathways are also listed with their KEGG entries." [GO:0006520, http://www.genome.jp/kegg/ "KEGG", MCW library:Handbooks of Biochemistry]