feat(pkg): improve xgenny dry run

[Pantani]

close #2565

Description

Improve the xgenny package by creating a custom runner to salve all modifications into a temporary folder and only apply and copy all files to the target directory later.

Changes

This PR removes the default dry and wet runners, avoiding running two generators. If everything works fine, only one will run into a temporary folder and be copied to the target folder.

[jeronimoalbi]

@Pantani the changes from #4057 might be the cause for the failing tests here. CI reported failing tests after merging the changes from the mentioned PR.

Maybe we should remove the -race until further investigation.

cc @julienrbrt