Add some basic tests of Data_Store class
Add some basic tests of Data_Store class

It's deprecated, but still exposed API and still used internally.

webmaster128/botan,randombit/botan,randombit/botan,Rohde-Schwarz-Cybersecurity/botan,Rohde-Schwarz-Cybersecurity/botan,webmaster128/botan,Rohde-Schwarz-Cybersecurity/botan,randombit/botan,Rohde-Schwarz-Cybersecurity/botan,Rohde-Schwarz-Cybersecurity/botan,webmaster128/botan,randombit/botan,webmaster128/botan,Rohde-Schwarz-Cybersecurity/botan,randombit/botan,webmaster128/botan