config: backport the rename of fastsync to blocksync

[williambanfield]

This is largely a cherry pick of #6755 with some additional fixups added where detected.
This change moves the blockchain package to a package called blocksync. Additionally, it renames the relevant uses of the term fastsync to blocksync.

closes: #9227

PR checklist

• Tests written/updated, or no tests needed
• CHANGELOG_PENDING.md updated, or no changelog entry needed
• Updated relevant documentation (docs/) and code comments, or no
  documentation updates needed

[cmwaters]

The config.toml is breaking right? say I had "v1" selected in v0.34. v0.37 won't correctly read it and think that it's not set and thus use the default ("v0"). I'm not sure how much of a problem this is as we've deprecated all the other options. In v0.37 we're essentially forcing everyone to use "v0".

[williambanfield]

It will read it correctly, it will just error:

tendermint/config/config.go

Line 900 in 2f9ea4a

case "v1", "v2":

EDIT:

I see what you're saying: the name of the toml table changed to [blocksync] so old configs will automatically get the default values because the table will not be set. I'll add a lot statement so that operators know to update.

[cmwaters]

Yeah this would be something that an automated migration set up would be able to handle. I think a warning in the logs upon start up makes sense