#1055 PLCgen: Construct POUs for input and/or output on request.

Changes made:

• First splits input processing from output processing by refactoring to 2 separate methods.
• Then adds the new option.
• Add code to generate input/output code in a POU instead of always in the main program.
• Add the possibility to add a POU to code storage. (Apparently generated transition POUs are added by passing them in with the code storage finishing call so they didn't need adding a POU.)
• Create a new test case (original button_lamp, but now with the new option set to "both-func").
• Update test output.
• Clarify org.eclipse.escet.common.app.framework.options.Option JavaDocs: link parseValue with getCmdLine in both directions.

End-user visible changes:

• PLCgen: 'Simplify values' option command line description typo fixed.
• PLCgen: Added a new option to specify the input/output code form.
• PLCgen: Improved the documentation of several of the generator's options.
• PLCgen: Improved the command line and GUI option descriptions of the 'PLC maximum iterations' option.

For the test output, the diff between the two tests is

diff -u button_lamp_s7-300/MAIN.scl button_lamp_xio_funcs_s7-300/MAIN.scl
--- button_lamp_s7-300/MAIN.scl	2024-11-04 11:44:28.464616084 +0100
+++ button_lamp_xio_funcs_s7-300/MAIN.scl	2024-11-14 15:09:31.204941556 +0100
@@ -16,6 +16,7 @@
         current_timer: BOOL;
         current_timer_1: BOOL;
         current_timer_t: REAL;
+        dummyResult: BOOL;
         edge_hw_button: BOOL;
         edge_hw_lamp: BOOL;
         edge_sup: BYTE;
@@ -101,12 +102,7 @@
      *------------------------------------------------------ *)
 
     (* --- Read PLC inputs. ---------------------------------------------------- *)
-    (* Read PLC input and write it to input variable "hw_button.bit". *)
-    "DB".hw_button_bit := in_hw_button_bit;
-    (* Read PLC input and write it to input variable "hw_button.bot". *)
-    "DB".hw_button_bot := in_hw_button_bot;
-    (* Read PLC input and write it to input variable "hw_button.bat". *)
-    "DB".hw_button_bat := in_hw_button_bat;
+    dummyResult := processInputs(TRUE);
 
     (* --- Initialize state or update continuous variables. -------------------- *)
     IF "DB".firstRun THEN
@@ -634,6 +630,5 @@
     END_WHILE;
 
     (* --- Write PLC outputs. -------------------------------------------------- *)
-    (* Write algebraic variable "hw_lamp.bit" to PLC output. *)
-    out_hw_lamp_bit := "DB".hw_lamp = hw_lamp_On;
+    dummyResult := processOutputs(TRUE);
 END_ORGANIZATION_BLOCK

Also, there are new files:

Only in button_lamp_xio_funcs_s7-300: processInputs.scl
Only in button_lamp_xio_funcs_s7-300: processOutputs.scl

This matches expectations.

Closes #1055 (closed)