add: private include header
add: macro encapsulation for assertion or error check
add: ESP_FAIL return code documentation in public headers
change: replaced all assertions by NVS_ASSERT_OR_RETURN macro
change: few internal function return values from void to esp_err_t
change: ESP_ERR_NVS_VALUE_TOO_LONG macro comment
* partition api changed from spi_flash* API to
esp_partition* API and is abstracted as a C++
interface.
* The old nvs encryption is still possible
* changed default unit test app partition table
* Partitions coming from esp_partition API are
checked for generic flash encryption. If yes,
an error is returned since generic flash
encryption isn't compatible with nvs
encryption
* esp32, esp32s2 tests don't require nvs_flash
but mbedtls now
Closes IDF-1340
Closes IDF-858