[wip] feat/dynamic fee vault

[bangyro]

DynamicFeeVault

• new account that is separate from existing FeeVault but can be used with fund_fee and claim_fee ix
• does not support fund_by_claiming_fee
• supports 2 token mint (token_0 and token_1)
• token_1 is optional (Pubkey::default is sentinel)
• supports new operations
  • add_user
  • remove_user
  • claim_unclaimed_fee
  • update_user_share
  • fund_by_whitelisted_action

fund_by_whitelisted_action

• similar to fund_by_claiming_fee but allows arbitrary program for claiming fee without program update
  • this is done through a whitelisting process (create_whitelisted_action)
• CPI into the program that is whitelisted to transfer token to token_0_vault and token_1_vault
• both token vaults index are validated if they exists