Reasonable defaults, isolate tests, EOS_LOGGING_LEVEL, EOS_CONFIG_DIR

* Add EOS_CONFIG_DIR to set config dir (relative path to EOS_DIR or
   absolute path).
    - config_folder_path read-only
    - config_file_path read-only
 * Default values to support app start with empty config:
    - latitude/longitude (Berlin)
    - optimization_ev_available_charge_rates_percent (null, so model
      default value is used)
    - Enable Akkudoktor electricity price forecast (docker-compose).
 * Fix some endpoints (empty data, remove unused params, fix types).
 * cacheutil: Use cache dir. Closes #240
 * Support EOS_LOGGING_LEVEL environment variable to set log level.
 * tests: All tests use separate temporary config
    - Add pytest switch --check-config-side-effect to check user
      config file existence after each test. Will also fail if user config
      existed before test execution (but will only check after the test has
      run).
      Enable flag in github workflow.
    - Globally mock platformdirs in config module. Now no longer required
      to patch individually.
      Function calls to config instance (e.g. merge_settings_from_dict)
      were unaffected previously.
 * Set Berlin as default location (default config/docker-compose).

tests/test_elecpriceimport.py

@@ -3,7 +3,6 @@ from pathlib import Path
 
 import pytest
 
-from akkudoktoreos.config.config import get_config
 from akkudoktoreos.core.ems import get_ems
 from akkudoktoreos.prediction.elecpriceimport import ElecPriceImport
 from akkudoktoreos.utils.datetimeutil import compare_datetimes, to_datetime
@@ -12,12 +11,9 @@ DIR_TESTDATA = Path(__file__).absolute().parent.joinpath("testdata")
 
 FILE_TESTDATA_ELECPRICEIMPORT_1_JSON = DIR_TESTDATA.joinpath("import_input_1.json")
 
-config_eos = get_config()
-ems_eos = get_ems()
-
 
 @pytest.fixture
-def elecprice_provider(reset_config, sample_import_1_json):
+def elecprice_provider(sample_import_1_json, config_eos):
     """Fixture to create a ElecPriceProvider instance."""
     settings = {
         "elecprice_provider": "ElecPriceImport",
@@ -26,7 +22,7 @@ def elecprice_provider(reset_config, sample_import_1_json):
     }
     config_eos.merge_settings_from_dict(settings)
     provider = ElecPriceImport()
-    assert provider.enabled() == True
+    assert provider.enabled()
     return provider
 
 
@@ -49,14 +45,14 @@ def test_singleton_instance(elecprice_provider):
     assert elecprice_provider is another_instance
 
 
-def test_invalid_provider(elecprice_provider):
+def test_invalid_provider(elecprice_provider, config_eos):
     """Test requesting an unsupported elecprice_provider."""
     settings = {
         "elecprice_provider": "<invalid>",
         "elecpriceimport_file_path": str(FILE_TESTDATA_ELECPRICEIMPORT_1_JSON),
     }
     config_eos.merge_settings_from_dict(settings)
-    assert elecprice_provider.enabled() == False
+    assert not elecprice_provider.enabled()
 
 
 # ------------------------------------------------
@@ -77,8 +73,9 @@ def test_invalid_provider(elecprice_provider):
         ("2024-10-27 00:00:00", False),  # DST change in Germany (25 hours/ day)
     ],
 )
-def test_import(elecprice_provider, sample_import_1_json, start_datetime, from_file):
+def test_import(elecprice_provider, sample_import_1_json, start_datetime, from_file, config_eos):
     """Test fetching forecast from Import."""
+    ems_eos = get_ems()
     ems_eos.set_start_datetime(to_datetime(start_datetime, in_timezone="Europe/Berlin"))
     if from_file:
         config_eos.elecpriceimport_json = None