Use macro per-test-file

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

tests/cases/identifiers.1-parsed.snap

@@ -0,0 +1,58 @@
+---
+source: tests/file_tests.rs
+expression: parsed
+info:
+  input: "{{= _name }}\n{{= a_name }}\n{{= name }}\n{{= _name1 }}\n{{= _namE }}\n{{= name1 }}"
+  context:
+    name1: Foo
+    _name: Foo
+    _namE: Foo
+    a_name: Foo
+    name: Foo
+    _name1: Foo
+---
+ParsedTemplate {
+    tokens: [
+        [LeftDelim]"{{" (0..2),
+        [WantsOutput]"=" (2..3),
+        [Whitespace]" " (3..4),
+        [Ident]"_name" (4..9),
+        [Whitespace]" " (9..10),
+        [RightDelim]"}}" (10..12),
+        [Whitespace]"\n" (12..13),
+        [LeftDelim]"{{" (13..15),
+        [WantsOutput]"=" (15..16),
+        [Whitespace]" " (16..17),
+        [Ident]"a_name" (17..23),
+        [Whitespace]" " (23..24),
+        [RightDelim]"}}" (24..26),
+        [Whitespace]"\n" (26..27),
+        [LeftDelim]"{{" (27..29),
+        [WantsOutput]"=" (29..30),
+        [Whitespace]" " (30..31),
+        [Ident]"name" (31..35),
+        [Whitespace]" " (35..36),
+        [RightDelim]"}}" (36..38),
+        [Whitespace]"\n" (38..39),
+        [LeftDelim]"{{" (39..41),
+        [WantsOutput]"=" (41..42),
+        [Whitespace]" " (42..43),
+        [Ident]"_name1" (43..49),
+        [Whitespace]" " (49..50),
+        [RightDelim]"}}" (50..52),
+        [Whitespace]"\n" (52..53),
+        [LeftDelim]"{{" (53..55),
+        [WantsOutput]"=" (55..56),
+        [Whitespace]" " (56..57),
+        [Ident]"_namE" (57..62),
+        [Whitespace]" " (62..63),
+        [RightDelim]"}}" (63..65),
+        [Whitespace]"\n" (65..66),
+        [LeftDelim]"{{" (66..68),
+        [WantsOutput]"=" (68..69),
+        [Whitespace]" " (69..70),
+        [Ident]"name1" (70..75),
+        [Whitespace]" " (75..76),
+        [RightDelim]"}}" (76..78),
+    ],
+}