feat: upgrade to v2.0.0 with major dependency updates

- Upgrade Solana dependencies from 2.3.x to 3.0.0 series
  - Upgrade solana-streamer-sdk from 0.4.13 to 0.5.0
  - Upgrade yellowstone-grpc from 8.0.0 to 9.0.0
  - Add new SPL token utility modules (spl_token.rs, spl_token_2022.rs,
  spl_associated_token_account.rs)
  - Remove deprecated gRPC protocol definitions (protos/ directory)
  - Remove event_subscription example and update all example dependencies
  - Update README documentation to reflect v2.0.0 changes
  - Refactor imports to use new dependency structure across examples

  BREAKING CHANGES:
  - Solana SDK upgraded to 3.0.0 with API changes
  - Removed gRPC protocol definitions
  - Updated import paths for SPL token operations

src/common/spl_token.rs

@@ -0,0 +1,48 @@
+use solana_program::pubkey;
+use solana_sdk::{
+    message::{AccountMeta, Instruction},
+    program_error::ProgramError,
+    pubkey::Pubkey,
+};
+
+pub const ID: Pubkey = pubkey!("TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA");
+
+pub fn close_account(
+    token_program_id: &Pubkey,
+    account_pubkey: &Pubkey,
+    destination_pubkey: &Pubkey,
+    owner_pubkey: &Pubkey,
+    signer_pubkeys: &[&Pubkey],
+) -> Result<Instruction, solana_sdk::program_error::ProgramError> {
+    // CloseAccount
+    let mut data = Vec::with_capacity(1);
+    data.push(9);
+    let mut accounts = Vec::with_capacity(3 + signer_pubkeys.len());
+    accounts.push(solana_sdk::message::AccountMeta::new(*account_pubkey, false));
+    accounts.push(solana_sdk::message::AccountMeta::new(*destination_pubkey, false));
+    accounts.push(solana_sdk::message::AccountMeta::new_readonly(
+        *owner_pubkey,
+        signer_pubkeys.is_empty(),
+    ));
+    for signer_pubkey in signer_pubkeys.iter() {
+        accounts.push(solana_sdk::message::AccountMeta::new_readonly(**signer_pubkey, true));
+    }
+    Ok(Instruction { program_id: *token_program_id, accounts, data })
+}
+
+pub fn initialize_account3(
+    token_program_id: &Pubkey,
+    account_pubkey: &Pubkey,
+    mint_pubkey: &Pubkey,
+    owner_pubkey: &Pubkey,
+) -> Result<Instruction, ProgramError> {
+    // InitializeAccount3
+    let mut data = Vec::with_capacity(33);
+    data.push(18);
+    data.extend_from_slice(owner_pubkey.as_ref());
+    let accounts = vec![
+        AccountMeta::new(*account_pubkey, false),
+        AccountMeta::new_readonly(*mint_pubkey, false),
+    ];
+    Ok(Instruction { program_id: *token_program_id, accounts, data })
+}