Function getSourceChain

getSourceChain(denomTrace, chain, chains): Promise<null | string>
Gets the source chain for a given denom trace.
Parameters
- denomTrace: string
  The denom trace string.
- chain: CosmosChainData
  The current chain data (CosmosChainData).
- chains: Record<string, CosmosChainData>
  A record of chain data indexed by chain IDs.
Returns Promise<null | string>
The source chain ID as a string or null if not found.