fix: add deposit fee and audit fixes

[skosito]

• add configurable deposit fee used in deposit/deposit spl instruction, initialize to 0.002 SOL (for already deployed contracts have to be called with authority)
• save bumps in pdas
• check if receiver is empty address for deposits

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 0% with 15 lines in your changes missing coverage. Please review.

Project coverage is 6.32%. Comparing base (2c18683) to head (af5caec).

Files with missing lines	Patch %	Lines
programs/protocol-contracts-solana/src/lib.rs	0.00%	15 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff            @@
##            main     #66      +/-   ##
========================================
- Coverage   6.53%   6.32%   -0.21%     
========================================
  Files          1       1              
  Lines        398     411      +13     
========================================
  Hits          26      26              
- Misses       372     385      +13     

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[lumtis]

Just to confirm, it fixes https://github.com/zeta-chain/protocol-private/issues/186 and https://github.com/zeta-chain/protocol-private/issues/184?

[brewmaster012]

LGTM

[skosito]

zeta-chain/protocol-private#184

yes and this one https://github.com/zeta-chain/protocol-private/issues/188 to make sure tests are working as intended