Chore: make dex changes backwards compatible

[pr0n00gler]

This PR aims to make changes made in #394 and #401 backwards compatible.

What exactly the PR does:

• in case of fix: change filled_limit_order_tranche query to inactive_limit_order_tranche #394 it introduces two deprecated HTTP endpoints to keep old endpoints working;
• in case of fix: pool_metadata proto capitalization #401 it basically reverts the change cause the change breaks backwards compatibility in case of Stargate queries where we can't just change field name in response. And since we are moving from Stargate to gRPC queries, we are gonna do the final renaming in a release where we completely remove Stargate from Neutron.

Related PRs:

• pool_metadata -> Pool_metadata neutron-sdk#142
• pool_metadata -> Pool_metadata neutron-dev-contracts#49

[pr0n00gler]

https://github.com/neutron-org/neutron-tests/actions/runs/8989515426