webkitpy: print nicer errors while linting expectations files, remove redundant tests

webkitpy: print nicer errors while linting expectations files, remove redundant tests
https://bugs.webkit.org/show_bug.cgi?id=76955

Reviewed by Adam Barth.

This change cleans up the errors that are printed so that the
are more "quickfix" compatible (path:lineno).

Also, there were a bunch of redundant tests between
layout_tests.models.test_expectations_unittest and
style.checkers.test_expectations_unittest. The latter should
just expect the former to do most of the testing.

* Scripts/webkitpy/layout_tests/models/test_expectations.py:
(TestExpectationParser._parse_modifiers):
(TestExpectations._report_errors):
(TestExpectations._add_skipped_tests):
* Scripts/webkitpy/layout_tests/models/test_expectations_unittest.py:
(test_parse_error_nonfatal):
(SemanticTests.test_bad_bugid):
* Scripts/webkitpy/style/checkers/test_expectations.py:
(TestExpectationsChecker.__init__):
* Scripts/webkitpy/style/checkers/test_expectations_unittest.py:
(TestExpectationsTestCase.assert_lines_lint):
(TestExpectationsTestCase.test_valid_expectations):
(TestExpectationsTestCase.test_invalid_expectations):
(TestExpectationsTestCase.test_tab):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@105948 268f45cc-cd09-0410-ab3c-d52691b4dbfc