samples, tests: convert string-based twister lists to YAML lists

Twister now supports using YAML lists for all fields that were written
as space-separated lists. Used twister_to_list.py script. Some artifacts
on string length are due to how ruamel dumps content.

Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>

tests/drivers/clock_control/nrf_clock_calibration/testcase.yaml

@@ -1,6 +1,11 @@
 tests:
   drivers.clock.nrf5_clock_calibration:
-    tags: drivers clock
-    platform_allow: nrf51dk_nrf51422 nrf52dk_nrf52832 nrf52840dk_nrf52840
+    tags:
+      - drivers
+      - clock
+    platform_allow:
+      - nrf51dk_nrf51422
+      - nrf52dk_nrf52832
+      - nrf52840dk_nrf52840
     integration_platforms:
       - nrf51dk_nrf51422