Refactor feed Blueprint usage

[danmash]

What to refactor?

• app/feed/routes.py use feed bp instead of scores

https://github.com/ClimateMind/climatemind-backend/blob/develop/app/feed/routes.py#L4

• app/feed/tests/test_feed_routes.py

Refactor reason

In #464 @brianpeiris noticed that we used the wrong Blueprint object in the feed.

Tests

• fix unit tests app/feed/tests/test_feed_routes.py
• check other usages for scoring.get_feed string and other URL usages
• check that this will not break the feed