test_app: Split panic test app into separate source files

- Added minor improvements to  `panic` test app
  * Replaced existing API to disable flash cache which did not disabled cache always
    (`esp_flash_default_chip->os_func->start(esp_flash_default_chip->os_func_data)`)
    with `spi_flash_enable_interrupts_caches_and_other_cpu`
  * Included some required headers explicitly (`esp_memory_utils.h` and `esp_heap_caps.h`)

tools/test_apps/system/panic/main/include/test_panic.h

@@ -0,0 +1,56 @@
+/*
+ * SPDX-FileCopyrightText: 2023 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#pragma once
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Utility functions */
+
+void die(const char* msg) __attribute__ ((noreturn));
+
+/* Functions causing an exception/panic in different ways */
+
+void test_abort(void);
+
+void test_abort_cache_disabled(void);
+
+void test_int_wdt(void);
+
+void test_task_wdt_cpu0(void);
+
+#if CONFIG_ESP_COREDUMP_ENABLE_TO_FLASH && CONFIG_SPIRAM_ALLOW_STACK_EXTERNAL_MEMORY
+void test_panic_extram_stack(void);
+#endif
+
+#if !CONFIG_FREERTOS_UNICORE
+void test_task_wdt_cpu1(void);
+void test_task_wdt_both_cpus(void);
+#endif
+
+void test_storeprohibited(void);
+
+void test_cache_error(void);
+
+void test_int_wdt_cache_disabled(void);
+
+void test_stack_overflow(void);
+
+void test_illegal_instruction(void);
+
+void test_instr_fetch_prohibited(void);
+
+void test_ub(void);
+
+void test_assert(void);
+
+void test_assert_cache_disabled(void);
+
+#ifdef __cplusplus
+}
+#endif