fix(svm): N-01 remove v3 from remaining functions and comments

[Reinis-FRP]

OZ identified following issue:

Pull request #861 renames several functions and types to remove the "V3" qualifier from the Solana spoke codebase. However, the renaming is incomplete:

• There is still a HandleV3AcrossMessage struct passed to a handle_v3_across_message function, with a HANDLE_V3_ACROSS_MESSAGE_DISCRIMINATOR constant.
• There are comments [1, 2] that mention functions with the "V3" qualifier.
• nativeDeposit.ts mentions a "V3" deposit.

Consider updating all functions and comments that mention "V3" for consistency with the rest of the code base.

This PR addresses the issue by removing the mention of "V3" from the rest of the SVM code base.
The only exception to this is handle_v3_across_message function and its related structs and constants as "V3" notion is also kept in the EVM where AcrossMessageHandler still has the handleV3AcrossMessage in its interface.

[linear]

ACX-4023 N-01 Incomplete Renaming

[md0x]

Perfect