Draft: testing/libetebase and testing/evolution-etesync: new aports

I originally added these packages in !23675 (merged) but did not commit to maintaining them at the time. It was merged but later removed again (650dce66 0aca3c4d) due to being unmaintained. I have been using these packages on Alpine for 3.5 years now, they work fine and the changes required for updates have so far been minimal. I am willing to commit to maintaining these packages and will open merge requests in the future when they are updated upstream.