CI - restyle script summary and annotations in PRs (#9184)

similar to .ino builder, prepare a short 'diff' summary of all the required changes
https://docs.github.com/en/actions/using-workflows/workflow-commands-for-github-actions#adding-a-job-summary

provide inline annotations, so it is apparent clang-format job is the
cause of the PR actions check failure
https://docs.github.com/en/actions/using-workflows/workflow-commands-for-github-actions#setting-a-notice-message

tests/test_restyle.py

@@ -0,0 +1,182 @@
+import unittest
+
+from restyle import changed_files_for_diff
+
+# small git-diff samples from https://queirozf.com/entries/git-diff-reference-and-examples
+
+
+class BaseTest(unittest.TestCase):
+    def testNewLine(self):
+        diff = """
+diff --git a/file.txt b/file.txt
+index 257cc56..3bd1f0e 100644
+--- a/file.txt
++++ b/file.txt
+@@ -1 +1,2 @@
+ foo
++bar
+"""
+        changed = changed_files_for_diff(diff)
+        self.assertEqual(1, len(changed))
+        self.assertEqual("file.txt", changed[0].file)
+        self.assertEqual(1, len(changed[0].lines))
+        self.assertEqual(1, changed[0].lines[0])
+
+        expected = """
+--- a/file.txt
++++ b/file.txt
+@@ -1 +1,2 @@
+ foo
++bar
+""".strip()
+        self.assertEqual(expected, changed[0].hunk.strip())
+
+    def testNewLines(self):
+        diff = """
+diff --git a/file.txt b/file.txt
+index 257cc56..3bd1f0e 100644
+--- a/file2.txt
++++ b/file2.txt
+@@ -1 +1,2 @@
+ foo
++bar
+ baz
+@@ -1 +10,2 @@
+ 222
+-222
+ 333
+@@ -1 +100,3 @@
+ aaa
++bbb
++ccc
+ ddd
+"""
+        changed = changed_files_for_diff(diff)
+        self.assertEqual(1, len(changed))
+        self.assertEqual("file2.txt", changed[0].file)
+
+        lines = changed[0].lines
+        self.assertEqual(3, len(lines))
+
+        first, second, third = lines
+        self.assertEqual(1, first)
+        self.assertEqual(10, second)
+        self.assertEqual(100, third)
+
+        expected = """
+--- a/file2.txt
++++ b/file2.txt
+@@ -1 +1,2 @@
+ foo
++bar
+ baz
+@@ -1 +10,2 @@
+ 222
+-222
+ 333
+@@ -1 +100,3 @@
+ aaa
++bbb
++ccc
+ ddd
+""".strip()
+        self.assertEqual(expected, changed[0].hunk.strip())
+
+    def testRemovedLineAndDeletedFile(self):
+        diff = """
+diff --git a/file.txt b/file.txt
+index 3bd1f0e..257cc56 100644
+--- a/file.txt
++++ b/file.txt
+@@ -1,2 +1 @@
+ foo
+-bar
+diff --git a/file2.txt b/file2.txt
+deleted file mode 100644
+index 85553e8..0000000
+--- a/file2.txt
++++ /dev/null
+@@ -1,2 +0,0 @@
+-aaaaaa
+-bbbbbb
+"""
+        changed = changed_files_for_diff(diff)
+        self.assertEqual(1, len(changed))
+        self.assertEqual("file.txt", changed[0].file)
+        self.assertEqual(1, len(changed[0].lines))
+        self.assertEqual(1, changed[0].lines[0])
+
+        expected = """
+--- a/file.txt
++++ b/file.txt
+@@ -1,2 +1 @@
+ foo
+-bar
+""".strip()
+        self.assertEqual(expected, changed[0].hunk.strip())
+
+    def testNewLineAndDeletedFile(self):
+        diff = """
+diff --git a/file.txt b/file.txt
+index 3bd1f0e..86e041d 100644
+--- a/file.txt
++++ b/file.txt
+@@ -1,2 +1,3 @@
+ foo
+ bar
++baz
+diff --git a/file2.txt b/file2.txt
+deleted file mode 100644
+index 85553e8..0000000
+--- a/file2.txt
++++ /dev/null
+@@ -1,2 +0,0 @@
+-aaaaaa
+-bbbbbb
+"""
+        changed = changed_files_for_diff(diff)
+        self.assertEqual(1, len(changed))
+        self.assertEqual("file.txt", changed[0].file)
+        self.assertEqual(1, len(changed[0].lines))
+        self.assertEqual(1, changed[0].lines[0])
+
+        expected = """
+--- a/file.txt
++++ b/file.txt
+@@ -1,2 +1,3 @@
+ foo
+ bar
++baz
+""".strip()
+        self.assertEqual(expected, changed[0].hunk.strip())
+
+    def testDeletedFile(self):
+        diff = """
+diff --git a/file2.txt b/file2.txt
+deleted file mode 100644
+index 85553e8..0000000
+--- a/file2.txt
++++ /dev/null
+@@ -1,2 +0,0 @@
+-aaaaaa
+-bbbbbb
+"""
+        changed = changed_files_for_diff(diff)
+        self.assertEqual(0, len(changed))
+
+    def testNewFile(self):
+        diff = """
+diff --git a/file3.txt b/file3.txt
+new file mode 100644
+index 0000000..a309e46
+--- /dev/null
++++ b/file3.txt
+@@ -0,0 +1 @@
++this is file3
+"""
+        changed = changed_files_for_diff(diff)
+        self.assertEqual(0, len(changed))
+
+
+if __name__ == '__main__':
+    unittest.main()