handover_test: rename test scripts from numbers to names

The meaningful names expose that some of those tests are apparently
quite similar.

With names like this it is far easier to see whether a specific scenario
is already tested or not, and find a test when looking for a specific
scenario.

Change-Id: I6f6d65d818fd1265e8ff94a2e0afba6392c50eb9
34 files changed