Remove priority mempool

[hvanz]

Closes #260

Note to reviewers: moving the files from mempool/v0 to mempool creates a dependency cycle mempool/clist_mempool_test.go -> internal/test/block.go -> state -> mempool. That's why I moved the function makeBlocks from internal/test/block.go to consensus/replay_test.go (the only place where it is used). The function MakeVoteSet in internal/test/commit.go was also creating a cycle, and it was unused, so I removed it.

Tasks

• Remove the files in mempool/v1.
• Remove the Version field from MempoolConfig.
• Remove v1 cases from node.
• Remove v1 cases from consensus and node tests.
• Remove mempool version from manifest in node generator for e2e tests.
• Remove last three fields (sender, priority, mempool_error) of ResponseCheckTx, which are related to the priority mempool.
• Move mempool/v0/* to mempool/.
• Update docs
• Update changelog

[github-actions]

This pull request has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[lasarojc]

The removal of v1 and renaming of v0 looks good to me

[sergio-mena]

Thanks @hvanz for this!