Naming and coding style convention, new linter tool. (#945)

* Makefile, Scripts: new linter
* About: remove ID from IC
* Firmware: remove double define for DIVC/DIVR
* Scripts: check folder names too. Docker: replace syntax check with make lint.
* Reformat Sources and Migrate to new file naming convention
* Docker: symlink clang-format-12 to clang-format
* Add coding style guide

applications/storage/filesystem_api_defines.h

@@ -0,0 +1,59 @@
+#pragma once
+#include <furi.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** Access mode flags */
+typedef enum {
+    FSAM_READ = (1 << 0), /**< Read access */
+    FSAM_WRITE = (1 << 1), /**< Write access */
+} FS_AccessMode;
+
+/** Open mode flags */
+typedef enum {
+    FSOM_OPEN_EXISTING = 1, /**< Open file, fail if file doesn't exist */
+    FSOM_OPEN_ALWAYS = 2, /**< Open file. Create new file if not exist */
+    FSOM_OPEN_APPEND = 4, /**< Open file. Create new file if not exist. Set R/W pointer to EOF */
+    FSOM_CREATE_NEW = 8, /**< Creates a new file. Fails if the file is exist */
+    FSOM_CREATE_ALWAYS = 16, /**< Creates a new file. If file exist, truncate to zero size */
+} FS_OpenMode;
+
+/** API errors enumeration */
+typedef enum {
+    FSE_OK, /**< No error */
+    FSE_NOT_READY, /**< FS not ready */
+    FSE_EXIST, /**< File/Dir alrady exist */
+    FSE_NOT_EXIST, /**< File/Dir does not exist */
+    FSE_INVALID_PARAMETER, /**< Invalid API parameter */
+    FSE_DENIED, /**< Access denied */
+    FSE_INVALID_NAME, /**< Invalid name/path */
+    FSE_INTERNAL, /**< Internal error */
+    FSE_NOT_IMPLEMENTED, /**< Functon not implemented */
+    FSE_ALREADY_OPEN, /**< File/Dir already opened */
+} FS_Error;
+
+/** FileInfo flags */
+typedef enum {
+    FSF_DIRECTORY = (1 << 0), /**< Directory */
+} FS_Flags;
+
+/**  Structure that hold file index and returned api errors  */
+typedef struct File File;
+
+/**  Structure that hold file info */
+typedef struct {
+    uint8_t flags; /**< flags from FS_Flags enum */
+    uint64_t size; /**< file size */
+} FileInfo;
+
+/** Gets the error text from FS_Error
+ * @param error_id error id
+ * @return const char* error text
+ */
+const char* filesystem_api_error_get_desc(FS_Error error_id);
+
+#ifdef __cplusplus
+}
+#endif