Fix NEL matching for faction / group Die Linke

[OpenHypervideo]

During the first processing (when only media data is available), Gruppe Die Linke ("new" parliamentary group cause the left lost faction status and is now only a group) can't be matched to a Wikidata Item via NEL.
As soon as the proceedings are processed, this is automatically fixed (cause in the proceedings it's just Die Linke, which matches to the faction).

Example

Just media:
https://github.com/OpenParliamentTV/OpenParliamentTV-Data-DE/blob/7f97dbbaac4396249fff0bd533031c0ee698c02f/processed/20205-session.json#L536

as soon as proceedings are processed:
https://github.com/OpenParliamentTV/OpenParliamentTV-Data-DE/blob/main/processed/20205-session.json#L18263

It was decided that on the platform side we use the DIE LINKE faction ID (Q1826856) internally for both faction (https://www.wikidata.org/wiki/Q1826856) and group (https://www.wikidata.org/wiki/Q125180315). We will do so in the future for other faction / group changes as well, cause the status change is not relevant functionally. Instead it just makes things super complicated every time a group looses or gains faction status.

Keeping that in mind, there are several possible solutions for this:

1. We add Gruppe Die Linke as alternativeLabel to the Wikidata Item of the faction so the group will be matched to the faction (a bit hacky, incorrect and might lead to a correction).
2. We somehow clean up the label, for example always remove the Gruppe string in https://github.com/OpenParliamentTV/OpenParliamentTV-Tools/blob/main/optv/parliaments/DE/nel/nel.py, resulting in the Die Linke faction being matched for both group and faction.
3. We add both faction and group to our list of factions on the platform, resulting in the group being detected correctly. Then we re-match the group to the faction during import (by adding a respective entry here: https://github.com/OpenParliamentTV/OpenParliamentTV-Platform/blob/main/data/ner-matching.php).

As this is automatically fixed as soon as the proceedings get processed, there's no immediate urgency to resolve this issue.