chore: rename config ChainName to ChainType

[bap2pecs]

Summary

when I am doing the devnet integration, I realized that ChainName can cause confusion. e.g. OPStackL2 is not really a consumer chain name, it's actually a type

after the changes, the config will looks like this

[Application Options]
; Logging level for all subsystems
LogLevel = info

; the type of the consumer chain
ChainType = babylon

there are only 3 possible types:

const (
	BabylonConsumerChainType   = "babylon"
	OPStackL2ConsumerChainType = "OPStackL2"
	WasmConsumerChainType      = "wasm"
)

Test Plan

make build
./build/fpd init --home ./.fpd

and see the generated config file

run tests

make test
make test-e2e-op
make test-e2e-babylon