Rename vendor_error_code to vendor_diagnostic_code

This is done to better reflect the purpose of the field, which is to
provide a vendor-specific diagnostic code for the error or the warning
that the sensor is reporting. The term "diagnostic" is more appropriate
than "error" in this context, as it encompasses both errors and
warnings.

Signed-off-by: Tiyash Basu <[email protected]>

Author: tiyash-basu-frequenz

proto/frequenz/api/common/v1/microgrid/electrical_components/electrical_components.proto

@@ -488,7 +488,7 @@ message ElectricalComponentDiagnostic {
 
   // Optional vendor-provided error code for the error, for vendor-specific
   // insights or more granular diagnostics.
-  optional uint32 vendor_error_code = 2;
+  optional uint32 vendor_diagnostic_code = 2;
 
   // Optional human-readable message providing additional context.
   string message = 3;

proto/frequenz/api/common/v1/microgrid/sensors/sensors.proto

@@ -173,9 +173,9 @@ message SensorDiagnostic {
   // A standardized error code representing the category of the issue.
   SensorDiagnosticCode diagnostic_code = 1;
 
-  // Optional vendor-provided error code for the error, for vendor-specific
+  // Optional vendor-provided diagnostic code for the error, for vendor-specific
   // insights or more granular diagnostics.
-  optional uint32 vendor_error_code = 2;
+  optional uint32 vendor_diagnostic_code = 2;
 
   // Optional human-readable message providing additional context.
   string message = 3;