platform-mc: Create Numeric sensor D-Bus object

Added numeric_sensor class. The NumericSensor class will create the
Numeric sensor D-Bus object. The class also handles sensor status and
exports its status to D-Bus interfaces.

tested: Verified on ast2600 EVB which is connected to a PLDM device
over I2C. bmcweb can display the state of numeric sensor.

Signed-off-by: Thu Nguyen <thu@os.amperecomputing.com>
Change-Id: I1c7de2e74100ed787ed2119896d3c5b36098dd96
diff --git a/meson.options b/meson.options
index d52506e..63726dd 100644
--- a/meson.options
+++ b/meson.options
@@ -174,3 +174,18 @@
     value: 8384512,
     description: 'OEM-IBM: max DMA size'
 )
+
+## Default Sensor Update Interval Options
+option(
+    'default-sensor-update-interval',
+    type: 'integer',
+    min: 1,
+    max: 4294967295,
+    description: '''The default sensor polling interval in milliseconds.
+                    The value will be used when the internal is not configured
+                    in the PLDM sensor PDRs use `updateInterval` field. `pldmd`
+                    will send `GetSensorReading` to get the PLDM sensor values
+                    of the monitoring terminus after each configured
+                    interval.''',
+    value: 999
+)
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