REF/TST: Add more pytest idiom to parsers tests

Adds more idiom to the following:

* parser/comment --> parser/test_comment
* parser/converters --> parser/test_converters
* parser/compression --> parser/test_compression

Builds off of pandas-devgh-23712.

Author: gfyoung

pandas/tests/io/parser/comment.py

@@ -1,3 +1,5 @@
+import os
+
 import pytest
 
 from pandas import read_csv, read_table
@@ -49,6 +51,11 @@ def csv_dir_path(datapath):
     return datapath("io", "parser", "data")
 
 
+@pytest.fixture
+def csv1(csv_dir_path):
+    return os.path.join(csv_dir_path, "test1.csv")
+
+
 _cParserHighMemory = CParserHighMemory()
 _cParserLowMemory = CParserLowMemory()
 _pythonParser = PythonParser()