Handle events in text interpolation; capture text events in choice lines; improve test script

test/tests/function ufcs args.lua

@@ -1,14 +1,18 @@
 local _={}
-_[5]={}
-_[4]={data="ok",tags=_[5]}
-_[3]={_[4]}
+_[6]={}
+_[5]={tags=_[6],text="k"}
+_[4]={tags=_[6],text="o"}
+_[3]={_[4],_[5]}
 _[2]={"return"}
 _[1]={"text",_[3]}
 return {_[1],_[2]}
 --[[
 { "text", { {
-      data = "ok",
-      tags = {}
+      tags = <1>{},
+      text = "o"
+    }, {
+      tags = <table 1>,
+      text = "k"
     } } }
 { "return" }
 ]]--