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/boot/mcuboot_recovery_retention/testcase.yaml

@@ -23,10 +23,16 @@ common:
 tests:
   mcuboot.recovery.retention:
     platform_allow: nrf52840dk_nrf52840
-    tags: mcuboot sysbuild recovery
+    tags:
+      - mcuboot
+      - sysbuild
+      - recovery
   mcuboot.recovery.retention.mem:
     platform_allow: nrf52840dk_nrf52840
-    extra_args: |
-        'OVERLAY_CONFIG="nrf52840dk_nrf52840_mem.conf"'
-        'DTC_OVERLAY_FILE="boards/nrf52840dk_nrf52840_mem.overlay"'
-    tags: mcuboot sysbuild recovery
+    extra_args:
+      - "'OVERLAY_CONFIG=\"nrf52840dk_nrf52840_mem.conf\"'"
+      - "'DTC_OVERLAY_FILE=\"boards/nrf52840dk_nrf52840_mem.overlay\"'"
+    tags:
+      - mcuboot
+      - sysbuild
+      - recovery

tests/boot/test_mcuboot/testcase.yaml

@@ -12,7 +12,10 @@ common:
 tests:
   boot.mcuboot:
     tags: mcuboot
-    platform_allow: frdm_k64f mimxrt1060_evk nrf52840dk_nrf52840
+    platform_allow:
+      - frdm_k64f
+      - mimxrt1060_evk
+      - nrf52840dk_nrf52840
     integration_platforms:
       - frdm_k64f
       - nrf52840dk_nrf52840