Add parsing for conditionals (cont.)

Signed-off-by: Marcel Müller <neikos@neikos.email>

tests/cases/3-instructions@multiple.snap

@@ -5,13 +5,13 @@ input_file: tests/cases/multiple.nomo
 ---
 [
     AppendContent {
-        content: "Hi there! My name is",
+        content: "Hi there! My name is" (0..20),
     },
     AppendContent {
-        content: " ",
+        content: " " (20..21),
     },
     LoadFromContextToSlot {
-        name: "name",
+        name: "name" (25..29),
         slot: VariableSlot {
             index: 0,
         },
@@ -22,10 +22,10 @@ input_file: tests/cases/multiple.nomo
         },
     },
     AppendContent {
-        content: " ",
+        content: " " (32..33),
     },
     LoadFromContextToSlot {
-        name: "lastname",
+        name: "lastname" (37..45),
         slot: VariableSlot {
             index: 1,
         },