[exporters] update iar teamplates so build artifacts end up in BUILD directory, not .build

Author: sg-

tools/export/iar/ewp.tmpl

@@ -20,15 +20,15 @@
 				</option>
 				<option>
 					<name>ExePath</name>
-					<state>$PROJ_DIR$\.build\Exe</state>
+					<state>$PROJ_DIR$\BUILD\Exe</state>
 				</option>
 				<option>
 					<name>ObjPath</name>
-					<state>$PROJ_DIR$\.build\Obj</state>
+					<state>$PROJ_DIR$\BUILD\Obj</state>
 				</option>
 				<option>
 					<name>ListPath</name>
-					<state>$PROJ_DIR$\.build\List</state>
+					<state>$PROJ_DIR$\BUILD\List</state>
 				</option>
 				<option>
 					<name>Variant</name>

tools/export/iar/iar_nucleo_f746zg.ewp.tmpl

@@ -16,15 +16,15 @@
         <wantNonLocal>1</wantNonLocal>
         <debug>1</debug>
         <option>
-          <state>$PROJ_DIR$\.build\iar_arm\Exe</state>
+          <state>$PROJ_DIR$\BUILD\Exe</state>
           <name>ExePath</name>
         </option>
         <option>
-          <state>$PROJ_DIR$\.build\iar_arm\Obj</state>
+          <state>$PROJ_DIR$\BUILD\Obj</state>
           <name>ObjPath</name>
         </option>
         <option>
-          <state>$PROJ_DIR$\.build\iar_arm\List</state>
+          <state>$PROJ_DIR$\BUILD\List</state>
           <name>ListPath</name>
         </option>
         <option>

tools/export/iar/iar_rz_a1h.ewp.tmpl

@@ -16,15 +16,15 @@
         <wantNonLocal>1</wantNonLocal>
         <debug>1</debug>
         <option>
-          <state>$PROJ_DIR$\.build\iar_arm\Exe</state>
+          <state>$PROJ_DIR$\BUILD\Exe</state>
           <name>ExePath</name>
         </option>
         <option>
-          <state>$PROJ_DIR$\.build\iar_arm\Obj</state>
+          <state>$PROJ_DIR$\BUILD\Obj</state>
           <name>ObjPath</name>
         </option>
         <option>
-          <state>$PROJ_DIR$\.build\iar_arm\List</state>
+          <state>$PROJ_DIR$\BUILD\List</state>
           <name>ListPath</name>
         </option>
         <option>