Social links in metadata page doesn't have the metadata page permalink.

[josegar74]

Fixes #8322

Test case:

1. Load ISO19139 metadata samples
2. Go to the metadata page of the Hydrological Basins in Africa (Sample record, please remove!) sample
3. Scroll down to the social links and click the mail icon

• Without the fix: it contains body=undefined instead of the metadata page permalink
• With the fix: it contains body=http://.... with the metadata page permalink

Checklist

• [X] I have read the contribution guidelines
• [X] Pull request provided for main branch, backports managed with label
• [ ] Good housekeeping of code, cleaning up comments, tests, and documentation
• [X] Clean commit history broken into understandable chucks, avoiding big commits with hundreds of files, cautious of reformatting and whitespace changes
• [X] 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