NVS: using esp_partition API

* 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

components/nvs_flash/src/nvs_pagemanager.hpp

@@ -18,7 +18,7 @@
 #include <list>
 #include "nvs_types.hpp"
 #include "nvs_page.hpp"
-#include "nvs_pagemanager.hpp"
+#include "partition.hpp"
 #include "intrusive_list.h"
 
 namespace nvs
@@ -31,7 +31,7 @@ public:
 
     PageManager() {}
 
-    esp_err_t load(uint32_t baseSector, uint32_t sectorCount);
+    esp_err_t load(Partition *partition, uint32_t baseSector, uint32_t sectorCount);
 
     TPageListIterator begin()
     {