program: Deprecate re-exports from spl-token-interface

#### Problem

We need pepole to know about spl-token-interface so they can start using
it, but we haven't really promoted it.

#### Summary of changes

Do the right thing, and make the deprecations loud in spl-token, and
stop using spl-token's re-exports everywhere in the repo.

Author: joncinque

Cargo.lock

@@ -40,8 +40,8 @@ solana-signer = "2.2.1"
 solana-transaction = "2.2.3"
 solana-transaction-error = "2.2.1"
 solana-system-interface = { workspace = true }
-spl-token = { version="^8", features=["no-entrypoint"] }
-spl-token-2022 = { version="^9", features=["no-entrypoint"] }
+spl-token-interface = "1"
+spl-token-2022-interface = "1"
 
 [lints]
 workspace = true

p-token/Cargo.toml

@@ -33,8 +33,12 @@ async fn amount_to_ui_amount() {
     .await
     .unwrap();
 
-    let amount_to_ui_amount_ix =
-        spl_token::instruction::amount_to_ui_amount(&spl_token::ID, &mint, 1000).unwrap();
+    let amount_to_ui_amount_ix = spl_token_interface::instruction::amount_to_ui_amount(
+        &spl_token_interface::ID,
+        &mint,
+        1000,
+    )
+    .unwrap();
 
     let tx = Transaction::new_signed_with_payer(
         &[amount_to_ui_amount_ix],
@@ -70,7 +74,8 @@ fn amount_to_ui_amount_with_maximum_decimals() {
     //  succeed and return the correct UI amount.
 
     let instruction =
-        spl_token::instruction::amount_to_ui_amount(&spl_token::ID, &mint, 20).unwrap();
+        spl_token_interface::instruction::amount_to_ui_amount(&spl_token_interface::ID, &mint, 20)
+            .unwrap();
 
     // The expected UI amount is "0.000....002" without the trailing zeros.
     let mut ui_amount = [b'0'; u8::MAX as usize + 1];
@@ -102,8 +107,12 @@ fn amount_to_ui_amount_with_u64_max() {
     // When we convert an u64::MAX amount using the mint, the transaction should
     // succeed and return the correct UI amount.
 
-    let instruction =
-        spl_token::instruction::amount_to_ui_amount(&spl_token::ID, &mint, u64::MAX).unwrap();
+    let instruction = spl_token_interface::instruction::amount_to_ui_amount(
+        &spl_token_interface::ID,
+        &mint,
+        u64::MAX,
+    )
+    .unwrap();
 
     // The expected UI amount is a `u64::MAX` with 255 decimal places.
     //   - 2 digits for `0.`

p-token/tests/amount_to_ui_amount.rs

@@ -52,8 +52,8 @@ async fn approve() {
 
     let delegate = Pubkey::new_unique();
 
-    let approve_ix = spl_token::instruction::approve(
-        &spl_token::ID,
+    let approve_ix = spl_token_interface::instruction::approve(
+        &spl_token_interface::ID,
         &account,
         &delegate,
         &owner.pubkey(),
@@ -77,7 +77,7 @@ async fn approve() {
     assert!(account.is_some());
 
     let account = account.unwrap();
-    let account = spl_token::state::Account::unpack(&account.data).unwrap();
+    let account = spl_token_interface::state::Account::unpack(&account.data).unwrap();
 
     assert!(account.delegate.is_some());
     assert!(account.delegate.unwrap() == delegate);

p-token/tests/approve.rs

@@ -52,7 +52,7 @@ async fn approve_checked() {
 
     let delegate = Pubkey::new_unique();
 
-    let approve_ix = spl_token::instruction::approve_checked(
+    let approve_ix = spl_token_interface::instruction::approve_checked(
         &TOKEN_PROGRAM_ID,
         &account,
         &mint,
@@ -79,7 +79,7 @@ async fn approve_checked() {
     assert!(account.is_some());
 
     let account = account.unwrap();
-    let account = spl_token::state::Account::unpack(&account.data).unwrap();
+    let account = spl_token_interface::state::Account::unpack(&account.data).unwrap();
 
     assert!(account.delegate.is_some());
     assert!(account.delegate.unwrap() == delegate);