Improve EOSdash.

Make EOSdash use UI components from MonsterUI to ease further development.

- Add a first menu with some dummy pages and the configuration page.
- Make the configuration scrollable.
- Add markdown component that uses markdown-it-py (same as used by
  the myth-parser for documentation generation).
- Add bokeh (https://docs.bokeh.org/) component for charts
- Added several prediction charts to demo
- Add a footer that displays connection status with EOS server
- Add logo and favicon

Update EOS server:

- Move error message generation to extra module
- Use redirect instead of proxy

Signed-off-by: Bobby Noelte <b0661n0e17e@gmail.com>

src/akkudoktoreos/prediction/elecpriceimport.py

@@ -63,6 +63,9 @@ class ElecPriceImport(ElecPriceProvider, PredictionImportProvider):
         return "ElecPriceImport"
 
     def _update_data(self, force_update: Optional[bool] = False) -> None:
+        if self.config.elecprice.provider_settings is None:
+            logger.debug(f"{self.provider_id()} data update without provider settings.")
+            return
         if self.config.elecprice.provider_settings.import_file_path:
             self.import_from_file(
                 self.config.elecprice.provider_settings.import_file_path,