suites/4g: Introduce sample handover test

This test currently only works with AmarisoftENB and srsUE, because:
* srsENB has no handover support yet
* AmarisoftUE doesn't provide any known way to verify handovers.

As a result, it usually runs with following filters and modifiers:
amarisoftenb-rftype@uhd+srsue-rftype@uhd+mod-enb-ncells@2+mod-enb-meas-enable

The get_counter() API may change in the future based on information
available from other implementations.

Change-Id: I0dff4af7e3a89804a03842ad4a4d697bca3a9773
diff --git a/sysmocom/scenarios/mod-enb-meas-enable.conf b/sysmocom/scenarios/mod-enb-meas-enable.conf
new file mode 100644
index 0000000..e3e841e
--- /dev/null
+++ b/sysmocom/scenarios/mod-enb-meas-enable.conf
@@ -0,0 +1,3 @@
+modifiers:
+  enb:
+  - enable_measurements: true