Fix PDA derivation logic

[irene-bbox]

Description

For the longest time, we were unable to derive a PDA. Fix the derivation logic to correctly derive a PDA.

Tasks

• invoke these surrogate functions to derive a PDA:
  • in the Rust contract use Pubkey::create_program_address()?
  • in the TypeScript client use PublicKey.findProgramAddress()
• hard code PDA seeds in both Rust and Typescript files (seeds must match up!)
• the TypeScript client passes some program instruction, and the program instructions contain a ProgramId. That ProgramId is the address of the Rust smart contract (program) after being deployed to devnet. So, you must first deploy the Rust contract, secondly you must fetch the deployed ProgramId, and lastly you'll pass that ProgramId to the .ts client
• the signer of the call to the TypeScript client, will be the signer of the blockchain transaction to derive the PDA, who will also be the funding account sponsoring the PDA derivation
• whenever you derive a PDA, consol.log these 3 pieces of info, which you'll need to interact with the PDA later on:
  • PDA public key
  • PDA seeds
  • PDA bump