ENSv2 GraphQL API: `Connection.totalCount`

[shrugs]

• include totalCount in connection if possible — might be difficult to derive for things like DomainsConnection.
• perhaps better exposed as a simple subdomainCount ala v1? or just inject into subdomains { totalCount } and hope the expectation that totalCount is available in other connections isn't that big of a deal

[shrugs]

injecting totalCount into t.connection proved quite annoying, so i've gone with the agonizing subdomainCount for simplicity