Is your feature request related to a problem? Please describe.

Some BTC projects are using signet for their testnet dapps. For example, BabylonChain.

Developers who want to explore interoperability between ZetaChain and other BTC dapps are limited to BTC dapps that use the BTC testnet.

Describe the solution you'd like
Support BTC signet on the ZetaChain testnet

Describe alternatives you've considered
N/A

Motivation and Context
We should make developing on ZetaChain as easy as possible for developers and that include supporting the testnet chains they need to build great dapps.

### Tasks
- [ ] https://github.com/zeta-chain/node/issues/2884
- [ ] https://github.com/zeta-chain/node/issues/2889
- [ ] https://github.com/zeta-chain/node/issues/2728