Harvesters / Check if the metadata schema of a metadata to update has changed

[josegar74]

Not a usual case, but some metadata schemas like Dutch datasets / services have different versions of the schemas and users can upgrade to the newer versions the existing metadata.

The harvesters code when updating a metadata, was not checking if the schema version changed, only updating the XML.

This pull request updates the following harvesters to deal with this use case:

• CSW
• Database
• GeoNetwork
• OAI-PMH
• SFTP
• WebDav

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

[CLAassistant]

All committers have signed the CLA.