Add COBOL language analyzer

[gianluca-sabena]

Add COBOL language to opengrok

What are the required steps to add a new language (COBOL) analyzer?

[vladak]

Universal ctags has COBOL support so it should be just a matter of adding analyzer for COBOL under the src/main/java/org/opengrok/indexer/analysis and src/main/jflex/analysis.

[vladak]

Here are some changesets that added analyzers for inspiration:

• TypeScript
• Verilog
• Terraform