fix missing usernames v2

[Hagellach37]

This fixes #687

check how many users are affected:

select 
count(*)
from users u 
where 1=1
	and username = ''
	and user_id not LIKE 'osm:%'
	and created >= '2024-01-01'
;

--> 403 users

Post-merge steps:

• update tasks contribution count in firebase --> update_task_contribution_count_in_firebase.py

docker compose run -d mapswipe_workers_creation python python_scripts/update_task_contribution_count_in_firebase.py

• set username in Firebase using https://github.com/mapswipe/python-mapswipe-workers/blob/dev/mapswipe_workers/python_scripts/add_missing_usernames_in_firebase.py

docker compose run -d mapswipe_workers_creation python python_scripts/add_missing_usernames_in_firebase.py

• update usernames in postgres --> run mapswipe_workers creation docker container