general: make time.tz.via_location user config lazy, move tests to my.tests package

also gets rid of the problematic reset_modules thingie

my/tests/shared_tz_config.py

@@ -0,0 +1,60 @@
+"""
+Helper to test various timezone/location dependent things
+"""
+
+from datetime import date, datetime, timezone
+from pathlib import Path
+
+import pytest
+from more_itertools import one
+
+from my.core.cfg import tmp_config
+
+
+@pytest.fixture(autouse=True)
+def config(tmp_path: Path):
+    # TODO could just pick a part of shared config? not sure
+    _takeout_path = _prepare_takeouts_dir(tmp_path)
+
+    class google:
+        takeout_path = _takeout_path
+
+    class location:
+        # fmt: off
+        home = (
+            # supports ISO strings
+            ('2005-12-04'                                       , (42.697842, 23.325973)), # Bulgaria, Sofia
+            # supports date/datetime objects
+            (date(year=1980, month=2, day=15)                   , (40.7128  , -74.0060 )), # NY
+            # check tz handling..
+            (datetime.fromtimestamp(1600000000, tz=timezone.utc), (55.7558  , 37.6173  )), # Moscow, Russia
+        )
+        # fmt: on
+        # note: order doesn't matter, will be sorted in the data provider
+
+    class time:
+        class tz:
+            class via_location:
+                fast = True  # some tests rely on it
+
+    with tmp_config() as cfg:
+        cfg.google = google
+        cfg.location = location
+        cfg.time = time
+        yield cfg
+
+
+def _prepare_takeouts_dir(tmp_path: Path) -> Path:
+    from .common import testdata
+
+    try:
+        track = one(testdata().rglob('italy-slovenia-2017-07-29.json'))
+    except ValueError:
+        raise RuntimeError('testdata not found, setup git submodules?')
+
+    # todo ugh. unnecessary zipping, but at the moment takeout provider doesn't support plain dirs
+    import zipfile
+
+    with zipfile.ZipFile(tmp_path / 'takeout.zip', 'w') as zf:
+        zf.writestr('Takeout/Location History/Location History.json', track.read_bytes())
+    return tmp_path