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

test/tests/optional arguments.lua

@@ -1,14 +1,30 @@
 local _={}
-_[5]={}
-_[4]={data="abc = abc = abc",tags=_[5]}
-_[3]={_[4]}
+_[9]={}
+_[8]={tags=_[9],text="abc"}
+_[7]={tags=_[9],text=" = "}
+_[6]={tags=_[9],text="abc"}
+_[5]={tags=_[9],text=" = "}
+_[4]={tags=_[9],text="abc"}
+_[3]={_[4],_[5],_[6],_[7],_[8]}
 _[2]={"return"}
 _[1]={"text",_[3]}
 return {_[1],_[2]}
 --[[
 { "text", { {
-      data = "abc = abc = abc",
-      tags = {}
+      tags = <1>{},
+      text = "abc"
+    }, {
+      tags = <table 1>,
+      text = " = "
+    }, {
+      tags = <table 1>,
+      text = "abc"
+    }, {
+      tags = <table 1>,
+      text = " = "
+    }, {
+      tags = <table 1>,
+      text = "abc"
     } } }
 { "return" }
 ]]--