drivers/sensor/mcp9808: Add MCP9808 temperature sensor driver

Add single-file module for the Microchip MCP9808 precision temperature
sensor. The module provides a class for reading the temperature and for
configuring the sensor. It has type/value checking for some of the
critical parts of the configuration as well as a debug mode for easier
testing during development.

It includes a test file designe to run directly on a board with a sensor
connected to test both the module and the sensor.

Both module and tests file are thoroughly documented in the code
directly. For more information read README.md on
https://github.com/MarcoMiano/mip-mcp9808

Author: MarcoMiano

micropython/drivers/sensor/mcp9808/manifest.py

@@ -0,0 +1,9 @@
+metadata(
+    description="Microchip MCP9808 temperature sensor driver",
+    version="1.0.0",
+    license="MIT",
+    author="Marco Miano",
+)
+
+# opt=2 so line numbers are preserved in case of exceptions
+module("mcp9808.py", opt=2)