Changes for RS485 mode

[AdrianSoundy]

Description

Add RS485 for ESP32 only

Motivation and Context

• Resolves Support for RS485 on ESP32 Home#673

How Has This Been Tested?

Simple test program to send data and check results on logic analyser

`

                    Configuration.SetPinFunction(34, DeviceFunction.COM2_RX);
		Configuration.SetPinFunction(13, DeviceFunction.COM2_TX);
		Configuration.SetPinFunction(12, DeviceFunction.COM2_RTS);

		sd = SerialDevice.FromId("COM2");

		sd.BaudRate = 230400;

		sd.DataBits = 8;
		sd.Parity = SerialParity.None;
		sd.StopBits = SerialStopBitCount.One;

		sd.Mode = SerialMode.RS485;

		inputDataReader = new DataReader(sd.InputStream);
		inputDataReader.InputStreamOptions = InputStreamOptions.Partial;

		sd.DataReceived += Sd_DataReceived;

		DataWriter outputDataWriter = new DataWriter(sd.OutputStream);

		while (true)
		{

			outputDataWriter.WriteString("abc\n");
			outputDataWriter.Store();


			Thread.Sleep(5);
		}

`

TX & RTS
RTS does seem to stay on a little longer than expected after last byte sent but that's done by ESP IDF

Types of changes

• Improvement (non-breaking change that improves a feature, code or algorithm)
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Config and build (change in the configuration and build system, has no impact on code or features)
• Dependencies (update dependencies and changes associated, has no impact on code or features)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

[nfbot]

@AdrianSoundy there are issues with the code style on the source files.
A PR was submitted with the code style fixes. Please review and merge the changes. See https://github.com/AdrianSoundy/nf-interpreter/pull/26.

Make sure you are using the project code style. Check the details here.

[josesimoes]

LGTM.
Can you please add a check to the other platforms to throw an NOT IMPLEMENTED exception when the SerialMode is set to RS485? That will make it clear to developers trying to use this feature on platforms that don't support or don't have this feature available.

[AdrianSoundy]

Tested on 469 Discovery and give not implemented exception

[nfbot]

@AdrianSoundy there are issues with the code style on the source files.
A PR was submitted with the code style fixes. Please review and merge the changes. See https://github.com/AdrianSoundy/nf-interpreter/pull/27.

Make sure you are using the project code style. Check the details here.