fix: Improve provider update error handling and add VRM provider settings validation (#887)

* fix: improve error handling for provider updates

Distinguishes failures of active providers from inactive ones.
Propagates errors only for enabled providers, allowing execution
to continue if a non-active provider fails, which avoids unnecessary
interruptions and improves robustness.

* fix: add provider settings validation for forecast requests

Prevents potential runtime errors by checking if provider settings are configured
before accessing forecast credentials.

Raises a clear error when settings are missing to help with debugging misconfigurations.

* refactor(load): move provider settings to top-level fields

Transitions load provider settings from a nested "provider_settings" object with provider-specific keys to dedicated top-level fields.\n\nRemoves the legacy "provider_settings" mapping and updates migration logic to ensure backward compatibility with existing configurations.

* docs: update version numbers and documantation

---------

Co-authored-by: Normann <github@koldrack.com>

src/akkudoktoreos/prediction/loadakkudoktor.py

@@ -56,9 +56,7 @@ class LoadAkkudoktor(LoadProvider):
             )
             # Calculate values in W by relative profile data and yearly consumption given in kWh
             data_year_energy = (
-                profile_data
-                * self.config.load.provider_settings.LoadAkkudoktor.loadakkudoktor_year_energy_kwh
-                * 1000
+                profile_data * self.config.load.loadakkudoktor.loadakkudoktor_year_energy_kwh * 1000
             )
         except FileNotFoundError:
             error_msg = f"Error: File {load_file} not found."