- 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`)
