More Infection State Translations

Add translation for 'Mild Infections' and also disable the "more" button if only 4 compartments exist.

I, the author of this PR checked the following requirements for good software quality:

[x] The code is properly formatted (I ran the formatter)
[x] The code is written with our software quality standards (I ran the linter)
[x] The code is written using our code style
[x] Extensive in source documentation has been added
[ ] ~~Unit and/or integration tests have been added~~
[x] All texts have been internationalized with at least the following languages:
- [x] English
- [x] German
[x] I tried addressing all new accessibility problems displayed in the console and documented if they can't be fixed
[ ] ~~I attached performance measurements to prevent performance degradation~~
[x] I added the changes to the next release section of the changelog

I, the reviewer checked the following things:

[ ] I ran the software once and tried all new and related functionality to this PR
[ ] I looked at all new and changed lines of code and commented on possible problems
[ ] I read the added documentation and checked if it is understandable and clear
[ ] I checked the added tests for completeness
[ ] I checked the internationalized strings for spelling errors
[ ] I checked the performance metrics for problems or unexplained degradation
[ ] I checked that the changes are noted in the changelog

DLR-SC / ESID