refactor: overhaul user activity extraction and fix review spoiler detection

[S1NJED]

I have fixed a little bug where liked list where treated as a movie (User.get_activity())

from this:

"9714176250": {
    "activity_type": "basic",
    "timestamp": "2025-09-01T01:14:09.687000Z",
    "content": {
        "action": "liked",
        "description": "oooguuh liked Vesey\u2019s Rotoscoping list",
        "movie": {
            "title": "Rotoscoping",
            "slug": "rotoscoping",
            "url": "https://letterboxd.com/film/rotoscoping/"
        }
    }
}

to this:

"9714176250": {
    "activity_type": "basic",
    "timestamp": "2025-09-01T01:14:09.687000Z",
    "content": {
        "action": "liked",
        "description": "oooguuh liked Vesey\u2019s Rotoscoping list",
        "list": {
            "title": "Rotoscoping",
            "url": "https://letterboxd.com/vesey/list/rotoscoping/"
        }
    }
}