Add WasmTendermintConfig struct implementing ClientConfig interface

[crodriguezvega]

Thank you @damiannolan for this suggestion.

In order to be able to write tests with the Tendermint wasm light client, a change in the testing package was made to specify where the light client is a regular Tendermint light client or a Tendermint wasm light client. A bool parameter was added to NewTendermintConfig to indicate this.

As proposed by @damiannolan, instead of using a bool to add behaviour to an existing type, add a new type (as that is what the ClientConfig interface is intended for):

• Remove UseWasmClient bool from TestChain, and setter SetWasm(bool).
• The CodeID field being added to the Coordinator type can be moved to the WasmTendermintConfig type as a new field. Add a new ClientConfig implementation to satisfy the interface:

type WasmTendermintConfig struct {
	TendermintConfig
	CodeID []byte // or string??
}

func NewWasmTendermintConfig(codeID []byte) *WasmTendermintConfig {
	return &WasmTendermintConfig{
		CodeID:                 codeID,
		TendermintConfig: TendermintConfig{
			TrustLevel:      DefaultTrustLevel,
			TrustingPeriod:  TrustingPeriod,
			UnbondingPeriod: UnbondingPeriod,
			MaxClockDrift:   MaxClockDrift,
		},
	}
}

func (wasmcfg *WasmTendermintConfig) GetClientType() string {
	// return exported.Wasm
	return "08-wasm"
}

• Add a WithClientConfig method to the testing Endpoint:

// WithClientConfig sets the client config on the associated Endpoint and returns it.
func (endpoint *Endpoint) WithClientConfig(clientCfg ClientConfig) *Endpoint {
	endpoint.ClientConfig = clientCfg
	return endpoint
}

[colin-axner]

Closing as this is not necessary. I think we will likely take an approach more in line with #4807 and #4808 as the testing pkg will need to avoid importing light client types