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/lfrfid/view/elements/icon_element.h

@@ -0,0 +1,17 @@
+#pragma once
+#include "generic_element.h"
+
+class IconElement : public GenericElement {
+public:
+    IconElement();
+    ~IconElement() final;
+    void draw(Canvas* canvas) final;
+    bool input(InputEvent* event) final;
+
+    void set_icon(uint8_t x = 0, uint8_t y = 0, const Icon* icon = NULL);
+
+private:
+    const Icon* icon = NULL;
+    uint8_t x = 0;
+    uint8_t y = 0;
+};