GitLab

* [Feature] add CSVDataset to load data from csv files

* add CSVDataset class file

* install pyyaml when running unit tests

* install pandas for unit tests

* utilize pydantic for YAML config check

* generate yaml and csv files during test

* make more keys as optional

* remove/rename several keys in yaml config and more tets though looks a bit clumsy

* fix test failure on mxnet

* pass /path/to/dataset instead of yaml path

* code refinement

* code refine

* change several yaml field such as feat and graph_id

* merge graph generation logic

* refine code

* Refactored_first_version

* DGLCSVDataset works for single heterograph

* add more tests

* fix test failure in mxnet

* add docstring

* use list comprehension for dict

* fix version in YAML

* refine data length assert

* use dict.pop directly

* remove ambiguous variable names

* refine graph id missing logic

* refine graph create call

* separate node/edge/graph data parser

* remove separator in DefaultDataParser

* refine validation error log for yaml field

* minor check

* refine code via dict.get()

* move load_from_csv into Node/Edge/GraphData

* move _parse_node/edge/graph_data into Node/Edge/GraphData

* refine id-related fields check

* check duplicate ntypes/etypes when load yaml

* refine docstring