Add attribute-size.h to src/app/zap-templates/chip-templates.json

[vivien-apple]

Problem

The templates extracted from #3464 that have landed in #3638 remove the previous gen/attribute-size.h file and get it merged into attribute-type.h.

That's not a bad thing but for the sake of being able to update the gen/ folder of examples independently during the migration phase I would prefer us to keep it. It would obligate the need to update src/app/attribute-size.cpp as suggested by #3346

For reference the change is:

--- a/src/app/util/attribute-size.cpp
+++ b/src/app/util/attribute-size.cpp
@@ -42,10 +42,9 @@
 //#include PLATFORM_HEADER
 
 #include "af.h"
+#include "gen/attribute-type.h"
 
-static const uint8_t attributeSizes[] = {
-#include "gen/attribute-size.h"
-};
+static const uint8_t attributeSizes[] = ZAP_GENERATED_ATTRIBUTE_SIZES;

This change means gen/ folder generated from AppBuilder and gen/folder generated from ZAP won't be able to lives at the same time into the tree.

I would prefer us to not have to change all the gen/ folder at the same time, just in case something is wrong in one of the cluster used by the all-clusters-app but that is unused for others examples such as lighting-app, lock-app and temperature-measurement-app

Summary of Changes

• Split back attribute-type.zapt into 2 different files. attribute-type.zapt and attribute-size.zapt