feat(backend): add asset comments

[LooFifteen]

This PR adds the following database tables:

comments(
    id UUID PRIMARY KEY DEFAULT uuidv7(),
    archived_at TIMESTAMPTZ,

    title TEXT NOT NULL,
    content TEXT NOT NULL,

    created_at TIMESTAMPTZ NOT NULL DEFAULT now(),
    created_by UUID REFERENCES users(id) NOT NULL
)

asset_comments(
    asset UUID REFERENCES assets(id) NOT NULL,
    comment UUID REFERENCES comments(id) NOT NULL
)

and the following routes:
GET /v1/assets/{id}/comments
POST /v1/assets/{id}/comments
PUT /v1/assets/{asset_id}/comments/{comment_id}