Google: conversion actions and remarketing / customer-match audiences

What we're asking for: two related things on Google - (a) create and read conversion actions, and (b) create remarketing or customer-match user lists and target them on Search and Display campaigns.

Why this matters to us: without a conversion action there is no meaningful "website conversions" objective. We can only optimise campaigns for clicks, which means telling a customer that their campaign can't be optimised for the thing they actually care about - form submissions and quote requests. Remarketing is the other half of the same
problem: re-reaching people who already visited is often the cheapest win available to a small advertiser, and we can't offer it. 

What happens today: neither conversion actions nor user lists are exposed through your API, as far as we can tell. The Google Ads API provides both (ConversionActionService and UserListService, including customer-match lists with hashed identifiers).

What "done" looks like for us:
- create a conversion action and read its status, so we can tell the customer whether measurement is actually live
- create a remarketing or customer-match list and reference it in campaign targeting
- read back which audiences a campaign is targeting