Add channels for all 4 modules in DEPFET quadrant

Description

Fully Power up and down a whole quadrant with 4 modules.

How Has This Been Tested?

Power up using:

import requests
from time import monotonic                      
def power_all_on():                              
     tstart = monotonic()                         
     print(requests.get("http://192.168.140.67/power?group=AON&output=on"))  # Group does not exist, validate that error handled, expect HTTP 406                                   
     print(requests.get("http://192.168.140.67/power?group=ASICS&output=on"))                                 
     print(requests.get("http://192.168.140.67/power?group=HV&output=on"))                                    
     print(requests.get("http://192.168.140.67/power?group=ISVOLTAGE&output=on"))                             
     print(requests.get("http://192.168.140.67/power?group=PLCSOURCE&output=on"))                             
     print("Took ", monotonic() - tstart) 

Power down using:

import requests
from time import monotonic
def off():
     tstart = monotonic()
     print(requests.get("http://192.168.140.67/alloff?token=CWH").json()['groups'])
     print("Took ", monotonic() - tstart)

Test protocol:

• Power up using power_all_on:
  Power procedure went module by module for each stage, prior to continuing to next stage.
  IS voltages were updated accordingly from 2.5v to 10v.
  IS channels were first turned on, their voltage not changed from initial MPOD configuration.

• Power down using alloff:
  Needs further investigation, some channels were not powered down on first attempt:
  

The above issue was due to too many SNMP commands sent to the MPOD controller.
This was mitigated by re-sending commands if a channel is on and no changes are observed after a few polls (5, chosen arbitrarily).

mpod.cpp

@@ -221,13 +221,34 @@ void setChannelStateAndWait(const IPAddress *ipAddr, const uint16_t channel, con
     snmp.loop();
 
     // Poll channel until it's settled
+    uint8_t loopCount = 0;
+    bool ramping = true;
+    bool settingChannelState = true;
     do {
         SNMP::Message *snmp_msg = mpod.read(channel);
         snmp.send(snmp_msg, *ipAddr, SNMP::Port::SNMP);
         delete snmp_msg;
+
         delay(MPOD_UPDATE_LATENCY);
         snmp.loop();
-    } while (mpod.isOn() != (bool)output || mpod.isRampingDown() || mpod.isRampingUp());
+        loopCount += 1;
+        ramping = (mpod.isRampingUp() || mpod.isRampingDown());
+        if (!ramping) {
+            if (mpod.isOn() == (bool)output) {
+                settingChannelState = false;
+            } else if (loopCount >= 5) {
+                // Resend set command
+                Serial.print("!Resend command to ");
+                Serial.println(channel);
+                SNMP::Message *snmp_msg = mpod.setChannelState(channel, output);
+                snmp.send(snmp_msg, *ipAddr, SNMP::Port::SNMP);
+                delay(MPOD_UPDATE_LATENCY);
+                snmp.loop();
+                delete snmp_msg;
+                loopCount = 0;
+            }
+        }
+    } while (settingChannelState);
 }
 
 void setChannelVoltageAndWait(const IPAddress *ipAddr, const uint16_t channel,