First try at Memory optimization

[Hoog-V]

What has changed

• Made the base class a template class, that statically allocates the internal buffer at compile-time
• Made the library header only (could not make it with source file as template classes must be defined in header file)
• Removed all the data helper functions and made them standalone, so that they don't get linked in when not used
• Create a Measurement_t structure which can be added to the encoder buffer, this Measurement_t supports for multiple data_types but is the size of the largest datatype (9-bytes), This is the artifact of using an union.
• The union Measurement_t helps to convert the different data-types to raw-bytes for transmission without the need of manual bit-shifts/ops.
• Made all the separate data helper functions static inline, so that it goes from this:

  
  static inline Measurement_t SetDigitalOutput(const uint8_t digital_output_val)
  {
      MeasurementData_t Data = {.DigitalGPIO = digital_output_val};
      return {.type = MEASUREMENT_TYPE_DIGITAL_OUTPUT, .val = Data};
  }

Measurement_t data = SetDigitalOutput(0);

To this:
```c
Measurement_t data = {.type =MEASUREMENT_TYPE_DIGITAL_OUTPUT,
                                           .val={.DigitalGPIO=0} };

It basically optimizes away all the function structure, and converts it in compile-time to a variable assignment.

• Compatible with both CMake and PlatformIO systems
• Added example to the examples folder
• Added comments and license banner
• Cppcheck succeeded without warnings

[majidsabbagh]

Seems good