oeqa/runtime/cases: Improve test dependency information

oeqa/runtime/cases: Improve test dependency information

Add the OEHasPackage decorator to a variety of tests so they determine
automatically if they should run against a given image.

To ensure tests can do this we need to move target operations such
as scp commands into the tests and out of the class startup/teardown.

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>