ekf2: verbose (DEBUG_BUILD) print status with Matrix improved print

* ekf2: verbose print status
 * matrix/Matrix improve print output
 * bold diagonal elements, print ring buffer entry size
 * print in scientific notation when >= 10 to respect max size

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Co-authored-by: bresch <brescianimathieu@gmail.com>

src/modules/ekf2/EKF/ekf.h

@@ -85,6 +85,8 @@ public:
 	// initialise variables to sane values (also interface class)
 	bool init(uint64_t timestamp) override;
 
+	void print_status();
+
 	// should be called every time new data is pushed into the filter
 	bool update();