[FL-1926] Flipper File Format addons (#753)

* Flipper file format: remove C wrapper
* Flipper file format: open append, float, uint32_t as array, delete key, value count
* Flipper file format: fix scratchpad location
* Flipper file format: add EOL on append
* SubGHZ keystore: update encryption type read and write
* Flipper File Format: enhanced version
* Flipper File Format: fix naming
* Flipper File Format: fix "open" subset naming
* Flipper File Format: tests
* Flipper File Format: file helper naming
* SubGHZ keystore: merge with current state of flipper file format
* Flipper File Format:  update make recipe
* Flipper File Format: open new file method

lib/flipper_file/flipper_file_i.h

@@ -0,0 +1,72 @@
+#include <stdint.h>
+#include <storage/storage.h>
+
+struct FlipperFile {
+    File* file;
+    Storage* storage;
+};
+
+/**
+ *  Value write type callback
+ */
+typedef bool (*flipper_file_cb)(File* file, const char* key, const void* data, uint16_t data_size);
+
+/**
+ * 
+ * @param flipper_file 
+ * @param key 
+ * @param cb 
+ * @param cb_key 
+ * @param cb_data 
+ * @param cb_data_size 
+ * @return bool 
+ */
+bool flipper_file_delete_key_and_call(
+    FlipperFile* flipper_file,
+    const char* key,
+    flipper_file_cb cb,
+    const char* cb_key,
+    const void* cb_data,
+    const uint16_t cb_data_size);
+
+/**
+ * Value types
+ */
+typedef enum {
+    FlipperFileValueHex,
+    FlipperFileValueFloat,
+    FlipperFileValueInt32,
+    FlipperFileValueUint32,
+} FlipperFileValueType;
+
+/**
+ * Internal write values function
+ * @param file 
+ * @param key 
+ * @param _data 
+ * @param data_size 
+ * @param type 
+ * @return bool 
+ */
+bool flipper_file_write_internal(
+    File* file,
+    const char* key,
+    const void* _data,
+    const uint16_t data_size,
+    FlipperFileValueType type);
+
+/**
+ * Internal read values function
+ * @param file 
+ * @param key 
+ * @param _data 
+ * @param data_size 
+ * @param type 
+ * @return bool 
+ */
+bool flipper_file_read_internal(
+    File* file,
+    const char* key,
+    void* _data,
+    const uint16_t data_size,
+    FlipperFileValueType type);