Add new table "nodeAggregateRatings", and move the ratings-summaries from node.extras to this new table

[Venryx]

Table structure draft:

CREATE TABLE app."nodeAggregateRatings" (
    process text NOT NULL PRIMARY KEY,
    node text NOT NULL PRIMARY KEY,
    type text NOT NULL,
    value real NOT NULL,
    "aggregationInfo" JSONB,
    "accessPolicy" text NOT NULL,
    "c_accessPolicyTargets" text[] NOT NULL
);