Add LBTC and USDT support; (#240)

* Add LBTC and USDT support;

Requires:
https://github.com/btcpayserver/btcpayserver/pull/1118
https://github.com/dgarage/NBXplorer/pull/198
https://github.com/btcpayserver/dockerfile-deps/pull/10

* add elementsd cli scripts

* simplify liquid integration

btcpay liquid PR adds all sub assets in one go so in docker specifying LBTC is enough

* bump images

* rename properly

* fix rpc

* add pruning for liquid node

* bump nbx

* add liquid more-memory

helpers.sh

@@ -17,6 +17,7 @@ install_tooling() {
                 "btcpayserver_monacoind" "monacoin-cli.sh" "Command line for your Monacoin instance" \
                 "btcpayserver_trezarcoind" "trezarcoin-cli.sh" "Command line for your Trezar instance" \
                 "btcpayserver_viacoind" "viacoin-cli.sh" "Command line for your Viacoin instance" \
+                "btcpayserver_elementsd" "elements-cli.sh" "Command line for your Elements/Liquid instance" \
                 "*" "btcpay-clean.sh" "Command line for deleting old unused docker images" \
                 "*" "btcpay-down.sh" "Command line for stopping all services related to BTCPay Server" \
                 "*" "btcpay-restart.sh" "Command line for restarting all services related to BTCPay Server" \