refactor: unify PDA AccountId construction via AccountId::for_{public,private}_pda

Addresses the following review comment:

- "I think this should be a constructor `AccountId::for_private_pda`.
  Consider also removing the existing `impl From<(ProgramId, Seed)> for
  AccountId` for public pdas in favor of a `AccountId::for_public_pda`
  to have a unified way of constructing pdas"

I replaced `impl From<(&ProgramId, &PdaSeed)> for AccountId` with
`AccountId::for_public_pda(program_id: &ProgramId, seed: &PdaSeed) ->
Self` and replaced the free function `private_pda_account_id(...)`
with `AccountId::for_private_pda(program_id: &ProgramId, seed:
&PdaSeed, npk: &NullifierPublicKey) -> Self`. Both live in an inherent
`impl AccountId` block in nssa/core/src/program.rs next to the PDA
derivation logic. Migrated all call sites across nssa/core,
nssa/src/state.rs, nssa/src/validated_state_diff.rs,
program_methods/guest/src/bin/privacy_preserving_circuit.rs,
programs/amm/core, programs/associated_token_account/core, the example
tail-call binary, and the ATA tutorial doc. Test function names that
referenced the old free function were also renamed
(private_pda_account_id_* to for_private_pda_*).

examples/program_deployment/src/bin/run_hello_world_with_authorization_through_tail_call_with_pda.rs

@@ -46,7 +46,7 @@ async fn main() {
     let program = Program::new(bytecode).unwrap();
 
     // Compute the PDA to pass it as input account to the public execution
-    let pda = AccountId::from((&program.id(), &PDA_SEED));
+    let pda = AccountId::for_public_pda(&program.id(), &PDA_SEED);
     let account_ids = vec![pda];
     let instruction_data = ();
     let nonces = vec![];