DCAT formatter improvements

[josegar74]

• Improve the functions to obtain record / resource URIs to produce full URIs.
• The original metadata can be ISO19115.3-2008 or ISO19139. For ISO19139, the extraction of languages was not defined.
• Use iso2 language code for rdf localised elements.
• Process all resource constraints.

Checklist

• I have read the contribution guidelines
• Pull request provided for main branch, backports managed with label
• Good housekeeping of code, cleaning up comments, tests, and documentation
• Clean commit history broken into understandable chucks, avoiding big commits with hundreds of files, cautious of reformatting and whitespace changes
• Clean commit messages, longer verbose messages are encouraged
• API Changes are identified in commit messages
• Testing provided for features or enhancements using automatic tests
• User documentation provided for new features or enhancements in manual
• Build documentation provided for development instructions in README.md files
• Library management using pom.xml dependency management. Update build documentation with intended library use and library tutorials or documentation

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