[Feature]: Remove name field from SpotProduct

[cdummett]

Feature Overview

In order to reduce the friction of proposing spot markets
We will remove the unnecessary name field from the SpotProduct message.
So that the docs are simplified

https://vegaprotocol.slack.com/archives/CAHA5EX0F/p1713438110844349

Specs

• Field is not mentioned anywhere in the specs, it was originally called base_quote_pair but this was removed in commit cad1bd5.

Tasks

when we build an instrument for a spot market, we have two name fields.

"instrument": {
    "name": "Bitcoin / Tether USD (Spot)",
    "code": "BTC/USDT-SPOT",
    "spot": {
        "baseAsset": None,
        "quoteAsset": None,
        "name": "BTC/USDT",
    },
}

The name field in the SpotProduct should be removed to simplify the proposal JSON any necessary changes made to the protos and APIs.