Add parsing for conditionals (cont.)

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

tests/cases/2-ast@interpolation.snap

@@ -6,27 +6,14 @@ input_file: tests/cases/interpolation.nomo
 TemplateAst {
     root: [
         StaticContent(
-            TemplateToken {
-                kind: Content,
-                source: "Hello! I'm",
-            },
+            "Hello! I'm" (0..10),
         ),
         Interpolation {
             prev_whitespace_content: Some(
-                TemplateToken {
-                    kind: Whitespace,
-                    source: " ",
-                },
+                " " (10..11),
             ),
-            wants_output: TemplateToken {
-                kind: WantsOutput,
-                source: "=",
-            },
             expression: VariableAccess(
-                TemplateToken {
-                    kind: Ident,
-                    source: "name",
-                },
+                "name" (15..19),
             ),
             post_whitespace_content: None,
         },