Add Java parser and example rule

[ericwb]

Is your feature request related to a problem? Please describe.
Support the analysis of java code

Describe the solution you'd like
Implement the java tree-sitter parser. To verify it works properly, create an example rule and test to iterate on.

Describe alternatives you've considered
n/a

Additional context
https://docs.oracle.com/javase/8/docs/api/

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