[lldb][gui] move TestGuiBasicDebug.py to lldb/test and update it

Between the time it was created and it was pushed upstream,
99451b44 has moved the existing
gui gui tests to lldb/test, so move this one too.
And update it to contain TestGuiBasic.py changes since the time
when it was based on that test.

Differential Revision: https://reviews.llvm.org/D85106