Make large dependencies optional

[antepusic]

Description

In order to make installing GQLAlchemy easier, this PR makes large dependencies (pyarrow, dgl and torch) optional:

pip install gqlalchemy ← skips the dependencies

pip install gqlalchemy[arrow] ← installs pyarrow:

dgl and torch are grouped because dgl-specific features also use torch for data structures:

• pip install gqlalchemy[dgl]← installs dgl and torch

Alternatively, users who wish to install PyG manually can install just torch:

• pip install gqlalchemy[torch_pyg]← installs torch

The all extra covers all above dependencies:

pip install gqlalchemy[all] ← installs everything

Pull request type

Please delete options that are not relevant.

• Build or packaging related changes

Related issues

Closes #178 #226 #227 #230

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have made corresponding changes to the documentation (docs#813)
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

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Reviewer checklist (the reviewer checks this part)

• Core feature implementation
• Tests
• Code documentation
• Documentation on memgraph/docs

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[Josipmrden]

Docs will also need to be updated