Feat: Add missing metrics for DefiLlama

[bvotteler]

Task split off from interlay/interbtc-ui#1520

Implement missing metrics needed to provide data to DefiLlama.
DefiLlama instructions: https://docs.llama.fi/list-your-project/submit-a-project

Alexei's notes (copied and edited from Discord):

Add adapters to DeFiLLama for the:

• DEX
• Lending

And update them for

• Staking

Here are examples for DeFiLlama adapters:

For our bridge collateral:
https://github.com/DefiLlama/DefiLlama-Adapters/tree/main/projects/interlay-collateral
For staking:
https://github.com/DefiLlama/DefiLlama-Adapters/tree/main/projects/interlay-staking

And here is an exmaple of acala-dex
https://github.com/DefiLlama/DefiLlama-Adapters/tree/main/projects/acala-dex

[bvotteler]

This issue may be obsolete after completing the following UI issue: interlay/interbtc-ui#1596
To be reviewed after that has been completed

[bvotteler]

Closing this issue. No further work on Squid expected following the completion of interlay/interbtc-ui#1596