POC for PDA upgrade

[skosito]

Couple of improvements (eg: https://github.com/zeta-chain/protocol-private/issues/182 https://github.com/zeta-chain/protocol-private/issues/186) would require extending PDA with new fields.

Purpose of this issue is to investigate and create POC/e2e test for adding new fields to PDA (eg: bump). Possible solutions:

• use realloc https://solana.com/developers/courses/program-optimization/program-architecture#account-flexibility-and-future-proofing - this looks like a preferred approach

• migrate to new PDA - seems more involved and not needed for now at least, it would mean that PDA have different address, moving all funds to new PDA etc

[lumtis]

As we discussed, I moved this one to the WithdrawAndCall epic #2941