releng: Add SWTBot Generator feature to target definition files

releng: Add SWTBot Generator feature to target definition files

This allows developers to use the SWTBot Generator by adding its
plug-ins from the target platform in their launch configuration.

The SWTBot Generator can then be launched with File -> New -> Other...
-> Run Test Recorder.

Change-Id: I845377851f442babd9cb108a0bebac61d6b06eca
Signed-off-by: Patrick Tasse <patrick.tasse@gmail.com>
Reviewed-on: https://git.eclipse.org/r/70279
Reviewed-by: Hudson CI
Reviewed-by: Matthew Khouzam <matthew.khouzam@ericsson.com>
Tested-by: Matthew Khouzam <matthew.khouzam@ericsson.com>