Support per-format NFPM overrides (as recently implemented in NFPM),
plus a pair or Goreleaser specific overrides, for "Replacements"
and "NameTemplate" (to address #640).
This keeps backward compatibility with existing config files:
settings at the root of the nfpm config section will still work as
previously (which is also useful to define common/shared settings
that we don't want to override anyway).
* refactor: removed goreleaserlib: moved all to main
* refactor: wip: snapshot
* fix: more pipes
* fix: more pipes
* fix: git tests
* fix: some other validate and publish usages
* fix: git dirty check when snapshoting
* fix: nfpm: use tag instead of version
* test: docker: print docker run output if registry fails
