Remove dev dependency on plerkle

[kespinola]

Goal

Message buffer agnostic parsing in release and dev environments.

Issue

https://github.com/metaplex-foundation/blockbuster/pull/38 removes plerkle as a dependency but it is still used in dev for test skaffolding.

Requirement

• Remove plerkle serialization from dev-dependency by switching to native solana structs for building transaction and account fixtures.