feat: add reason to BlockResponse messages

[amirvalhalla]

Description

add reason of rejection to block response

Related issue(s)

If this Pull Request is related to an issue, mention it here.

• Fixes Sync: Adding rejection reason to blocks response message #526

[codecov]

Codecov Report

Merging #607 (6bfa148) into main (6c36120) will decrease coverage by 0.29%.
Report is 3 commits behind head on main.
The diff coverage is 80.00%.

@@            Coverage Diff             @@
##             main     #607      +/-   ##
==========================================
- Coverage   83.46%   83.17%   -0.29%     
==========================================
  Files         154      154              
  Lines        7292     7287       -5     
==========================================
- Hits         6086     6061      -25     
- Misses        922      939      +17     
- Partials      284      287       +3     

[b00f]

The main idea behind this PR is to provide a message to peers once their request is rejected. There are several reasons why a request might be rejected. For example, the peer is not known (here), or they request a block that we don't have (here), etc.

In my opinion, we should not consider a rejected request as a failure(or byzantine). It might be, but we can't consider it as such. Consequently, our current practice of increasing the failure counter is incorrect. In this context, we could merge the Busy and Rejected codes. I'm sorry, I didn't notice earlier that we were adding to the failure counter.

Please note that a reason could be added as a new parameter for the NewBlocksResponseMessage function.

[amirvalhalla]

The main idea behind this PR is to provide a message to peers once their request is rejected. There are several reasons why a request might be rejected. For example, the peer is not known (here), or they request a block that we don't have (here), etc.

In my opinion, we should not consider a rejected request as a failure(or byzantine). It might be, but we can't consider it as such. Consequently, our current practice of increasing the failure counter is incorrect. In this context, we could merge the Busy and Rejected codes. I'm sorry, I didn't notice earlier that we were adding to the failure counter.

Please note that a reason could be added as a new parameter for the NewBlocksResponseMessage function.

request changes resolved, please review.