[BeforeSend Hook]: Merge TrackBeforeSend and BlockBeforeSend

[AlpinYukseloglu]

Background

After the patch in #6757, the distinction between TrackBeforeSend and BlockBeforeSend no longer makes sense to make, as the only difference between the two were that one was metered and the other wasn't, and now both are metered.

Suggested Design

• Combine TrackBeforeSend and BlockBeforeSend into a single BeforeSend message/hook

Acceptance Criteria

• All new and existing tests pass
• It is confirmed that this isn't actively in use by important contracts and that the API break is okay

[mattverse]

@AlpinYukseloglu I don't quite follow the reason they should be merged yet, can you elaborate more?

The key difference between the two are the API design, where one returns an error and one does not. That is, contracts can use TrackBeforeSend when they have an instance where contract needs to be called but has an error that needs to be gracefully silenced and use BlockBeforeSend to actually stop the send action from happening.