Refactor to remove redundant initialization and add NVS storage tests

- Removed unnecessary calls to relay_chn_create and g_is_component_initialized in multiple test cases across test_relay_chn_core_single.c, test_relay_chn_listener_multi.c, and test_relay_chn_listener_single.c.
- Introduced new test files for NVS functionality: test_relay_chn_nvs_multi.c and test_relay_chn_nvs_single.c, covering initialization, direction setting, invalid parameters, and erase operations.
- Updated partition table configuration to support NVS storage, including the addition of a new partition file part_nvs.csv.
- Adjusted sdkconfig files to enable NVS support and configure custom partition settings for relay channels.

test_apps/main/CMakeLists.txt

@@ -2,6 +2,8 @@
 set(srcs "test_common.c"
          "test_app_main.c")
 
+set(incdirs ".")
+
 # === Selective compilation based on channel count ===
 if(CONFIG_RELAY_CHN_COUNT GREATER 1)
     list(APPEND srcs "test_relay_chn_core_multi.c"
@@ -14,16 +16,27 @@ endif()
 if(CONFIG_RELAY_CHN_ENABLE_TILTING)
     if(CONFIG_RELAY_CHN_COUNT GREATER 1)
         list(APPEND srcs "test_relay_chn_tilt_multi.c")
-    else()    
+    else()
         list(APPEND srcs "test_relay_chn_tilt_single.c")
     endif()
 endif()
 
+if(CONFIG_RELAY_CHN_ENABLE_NVS)
+    list(APPEND incdirs "../../private_include")
+    list(APPEND srcs "../../src/relay_chn_nvs.c")
+    if(CONFIG_RELAY_CHN_COUNT GREATER 1)
+        list(APPEND srcs "test_relay_chn_nvs_multi.c")
+    else()
+        list(APPEND srcs "test_relay_chn_nvs_single.c")
+    endif()
+endif()
+
+
 # In order for the cases defined by `TEST_CASE` to be linked into the final elf,
 # the component can be registered as WHOLE_ARCHIVE
 idf_component_register(
     SRCS ${srcs}
-    INCLUDE_DIRS "."
+    INCLUDE_DIRS ${incdirs}
     REQUIRES unity relay_chn
     WHOLE_ARCHIVE
 )