Furi: core refactoring and CMSIS removal part 2 (#1410)

* Furi: rename and move core
* Furi: drop CMSIS_OS header and unused api, partially refactor and cleanup the rest
* Furi: CMSIS_OS drop and refactoring.
* Furi: refactoring, remove cmsis legacy
* Furi: fix incorrect assert on queue deallocation, cleanup timer
* Furi: improve delay api, get rid of floats
* hal: dropped furi_hal_crc
* Furi: move DWT based delay to cortex HAL
* Furi: update core documentation

Co-authored-by: hedger <hedger@nanode.su>

furi/core/memmgr.h

@@ -0,0 +1,40 @@
+/**
+ * @file memmgr.h
+ * Furi: memory managment API and glue
+ */
+
+#pragma once
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include "check.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// define for test case "link against furi memmgr"
+#define FURI_MEMMGR_GUARD 1
+
+/** Get free heap size
+ *
+ * @return     free heap size in bytes
+ */
+size_t memmgr_get_free_heap(void);
+
+/** Get total heap size
+ *
+ * @return     total heap size in bytes
+ */
+size_t memmgr_get_total_heap(void);
+
+/** Get heap watermark
+ *
+ * @return     minimum heap in bytes
+ */
+size_t memmgr_get_minimum_free_heap(void);
+
+#ifdef __cplusplus
+}
+#endif