Add support for reindexing all metadata of a harvester

[tobias-hotz]

This PR adds support for reindexing all the metadata records of a harvester. This is useful if a harvester run occured while the Elasticsearch instance had issues. Without this PR, you need to reindex all metadata (which may take a long time for huge catalogs) or select all affected metadata by hand (which may not be possible if the new metadata is not in the index).
With this PR, a new button is added in the harvester view that allows all records to be reindex. The backend code is mostly aligned to be similar to the existing code.

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

Funded by LGL BW

[josegar74]

Thanks for the changes. Tested and works fine.