Add LOBID fetcher

[aqurilla]

Fixes koppor#386 by adding the LOBID fetcher (https://lobid.org/resources/api)

Mandatory checks

• Change in CHANGELOG.md described in a way that is understandable for the average user (if applicable)
• Tests created for changes (if applicable)
• Manually tested changed features in running JabRef (always required)
• Screenshots added in PR description (for UI changes)
• Checked developer's documentation: Is the information available and up to date? If not, I outlined it in this pull request.
• Checked documentation: Is the information available and up to date? If not, I created an issue at https://github.com/JabRef/user-documentation/issues or, even better, I submitted a pull request to the documentation repository.

[Siedlerchr]

Yeah! Thanks for tackling this issue. I think if we need some support, we can probably also ask at their repo:
https://github.com/hbz/lobid-resources

[aqurilla]

@Siedlerchr Sounds good!

[Siedlerchr]

Is your PR ready for review? Looks already very good

[aqurilla]

@Siedlerchr yes this is ready for review!