Qthrottler and debouncer (#62)

* initial working throttler

* complete typing and docs

* basic test

* fix future subscript

* touch ups

* Update src/superqt/utils/_throttler.py

Co-authored-by: Grzegorz Bokota <bokota+github@gmail.com>

* Update src/superqt/utils/_throttler.py

Co-authored-by: Grzegorz Bokota <bokota+github@gmail.com>

* Update src/superqt/utils/_throttler.py

Co-authored-by: Grzegorz Bokota <bokota+github@gmail.com>

Co-authored-by: Grzegorz Bokota <bokota+github@gmail.com>

tests/test_throttler.py

@@ -0,0 +1,43 @@
+from unittest.mock import Mock
+
+from superqt.utils import qdebounced, qthrottled
+
+
+def test_debounced(qtbot):
+    mock1 = Mock()
+    mock2 = Mock()
+
+    @qdebounced(timeout=5)
+    def f1() -> str:
+        mock1()
+
+    def f2() -> str:
+        mock2()
+
+    for _ in range(10):
+        f1()
+        f2()
+
+    qtbot.wait(5)
+    mock1.assert_called_once()
+    assert mock2.call_count == 10
+
+
+def test_throttled(qtbot):
+    mock1 = Mock()
+    mock2 = Mock()
+
+    @qthrottled(timeout=5)
+    def f1() -> str:
+        mock1()
+
+    def f2() -> str:
+        mock2()
+
+    for _ in range(10):
+        f1()
+        f2()
+
+    qtbot.wait(5)
+    assert mock1.call_count == 2
+    assert mock2.call_count == 10