RPC getaddressinfo should use CWallet::GetKeyOrigin #14682

Currently the getaddressinfo RPC call accesses the wallet metadata directly:

        if (!meta->hdKeypath.empty()) {
            ret.pushKV("hdkeypath", meta->hdKeypath);
            ret.pushKV("hdseedid", meta->hd_seed_id.GetHex());
            if (!meta->master_key_id.IsNull()) {
                ret.pushKV("hdmasterkeyid", meta->master_key_id.GetHex());
            }
        }

CWallet::GetKeyOrigin was introduced in https://github.com/bitcoin/bitcoin/pull/13723/commits/03a99586a398ee38f40c3b72d24c6a2ba4b88579

Probably not urgent, but I noticed this issue while debugging a problem on an experimental branch where getaddressinfo showed the origin info just fine but GetKeyOrigin failed.

It's been changed a bit, but still relies on unencapsulated access to pwallet->mapKeyMetadata:

        if (meta->has_key_origin) {
            ret.pushKV("hdkeypath", WriteHDKeypath(meta->key_origin.path));
            ret.pushKV("hdseedid", meta->hd_seed_id.GetHex());
            ret.pushKV("hdmasterfingerprint", HexStr(meta->key_origin.fingerprint, meta->key_origin.fingerprint + 4));
        }

A good time to fix this is while adding origin info the GUI, which is probably useful for hardware wallet address verification, since devices often echo the derivation path (#14145).

It now uses spk_man->GetMetadata().