Send raw error message to client and add extra method to resolve error message.

Avoids powered-off computers showing "bus incomplete" after load.

src/main/java/li/cil/oc2/client/gui/AbstractMachineTerminalScreen.java

@@ -185,7 +185,7 @@ public abstract class AbstractMachineTerminalScreen<T extends AbstractMachineTer
             Sprites.ENERGY_BAR.drawFillY(stack, x, y, menu.getEnergy() / (float) menu.getEnergyCapacity());
         }
 
-        terminalWidget.render(stack, mouseX, mouseY, menu.getVirtualMachine().getBootError());
+        terminalWidget.render(stack, mouseX, mouseY, menu.getVirtualMachine().getError());
     }
 
     @Override

src/main/java/li/cil/oc2/client/renderer/blockentity/ComputerRenderer.java

@@ -183,7 +183,7 @@ public final class ComputerRenderer implements BlockEntityRenderer<ComputerBlock
             return;
         }
 
-        final Component bootError = computer.getVirtualMachine().getBootError();
+        final Component bootError = computer.getVirtualMachine().getError();
         if (bootError == null) {
             return;
         }

src/main/java/li/cil/oc2/common/vm/AbstractVirtualMachine.java

@@ -126,6 +126,18 @@ public abstract class AbstractVirtualMachine implements VirtualMachine {
     @Override
     @Nullable
     public Component getBootError() {
+        return bootError;
+    }
+
+    @Override
+    @OnlyIn(Dist.CLIENT)
+    public void setBootErrorClient(@Nullable final Component value) {
+        bootError = value;
+    }
+
+    @Override
+    @Nullable
+    public Component getError() {
         switch (busState) {
             case SCAN_PENDING:
             case INCOMPLETE:
@@ -145,12 +157,6 @@ public abstract class AbstractVirtualMachine implements VirtualMachine {
         return null;
     }
 
-    @Override
-    @OnlyIn(Dist.CLIENT)
-    public void setBootErrorClient(@Nullable final Component value) {
-        bootError = value;
-    }
-
     @Override
     public void start() {
         if (runState == VMRunState.RUNNING) {

src/main/java/li/cil/oc2/common/vm/VirtualMachine.java

@@ -26,6 +26,9 @@ public interface VirtualMachine {
     @OnlyIn(Dist.CLIENT)
     void setBootErrorClient(@Nullable Component value);
 
+    @Nullable
+    Component getError();
+
     boolean isRunning();
 
     void start();