feat(handler): requirement class

implement POC of "smart defaults", pin newest pydantic 1.5.1 (resolves
issue with BaseFilter signature inspection)

tests/test_dispatcher/test_requirement.py

@@ -0,0 +1,17 @@
+# todo
+from aiogram.dispatcher.requirement import require, CallableRequirement
+
+tick_data = {"ticks": 0}
+
+
+def test_require():
+    x = require(lambda: "str", use_cache=True, cache_key=0)
+    assert isinstance(x, CallableRequirement)
+    assert callable(x) & callable(x.callable)
+    assert x.cache_key == 0
+    assert x.use_cache
+
+
+class TestCallableRequirementCache:
+    def test_cache(self):
+        ...