Feature/schema to oracle sql

[ana-estrada]

This pull request adds support to generate an Oracle SQL Property Graph

Two main functionalities are provided:

• Translation of already existent graph schema into Oracle Property Graph DDL.
  For example, for the example_schema included in the repository, this command can be used:
  python ./examples/transform_schema_to_cpg.py --file example_schema --graph_name my_movie_graph --domain movie --subdomain movielens --csv_dir examples/generated_data/scripts/csv_files/ --control_dir examples/generated_controls/movie_graph/ --credentials scott/tiger@localhost:1521/my_pdb
  This command will generate

1. A SQL script with SQL DDLs to create vertex tables, edge tables and a Property Graph
2. CTL files for each one of the CSV files
3. A SH script with SQLLDR statements to load data from existent CSV files

Also a prototype to generate Oracle Property Graph is added. This uses the same existent approach to
generate JSON schema, but generating SQL statements instead.