Add fixed IDs to other blocks that can be glowed in the toolbox.

Prevent switching tabs while one of these blocks is glowing from
crashing because it is given a new ID.

src/lib/make-toolbox-xml.js

@@ -336,12 +336,12 @@ const control = `
                 </shadow>
             </value>
         </block>
-        <block type="control_forever"/>
+        <block id="forever" type="control_forever"/>
         ${blockSeparator}
         <block type="control_if"/>
         <block type="control_if_else"/>
-        <block type="control_wait_until"/>
-        <block type="control_repeat_until"/>
+        <block id="wait_until" type="control_wait_until"/>
+        <block id="repeat_until" type="control_repeat_until"/>
         ${blockSeparator}
         <block type="control_stop"/>
         ${blockSeparator}