Use optimized checksumming when loading database

[btoews]

I wanted to make sure we like the new API before merging superfly/ltx#56, so this PR targets that branch currently. If we're happy with how this PR looks, I'll merge the ltx one and rebase this one.

Update: I merged and cut a new release for superfly/ltx#56. I rebased this branch, so it should be ready to go.

[btoews]

Looks like CI is broken

Run sudo apt install -y fuse3 libsqlite3-dev consul

WARNING: apt does not have a stable CLI interface. Use with caution in scripts.

Reading package lists...
Building dependency tree...
Reading state information...
Package consul is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source

E: Package 'consul' has no installation candidate

Update: Fixed it

[btoews]

I merged and cut a new release for superfly/ltx#56. I rebased this branch, so it should be ready to go.

[btoews]

I'm seeing the hoped-for boot speed improvements running this branch in production 🎉