feat: tasks and lockfiles

[Yohe-Am]

Describe your change

First crack at tasks.

Motivation and context

#10

Migration notes

• The ghjk executable now looks for or generates a .ghjk directory next to ghjk.ts.
• $GHJK_CONFIG has been renamed to $GHJKFILE
• $GHJK_DIR meaning has been changed to point at the discovered .ghjk dir as opposed to the ghjk share dir.
• ghjk.ts serialization might be skipped if the it's been determined that no important inputs have changed.
• InstallConfig.version is now checked against the versions returned by the port's listAll implementation.
• Resolved InstallConfig.version is now cached in the lockfile. For now, manually remove the lockfile to re-resolve everything.
• install and download steps on a port are skipped if they'd previously successfully completed on the same InstallConfig.

Checklist

• The change come with new or modified tests
• Hard-to-understand functions have explanatory comments
• End-user documentation is updated to reflect the change

[zifeo]

Looks good so far

[zifeo]

One small suggestion, otherwise lgtm

[zifeo]

Love the new lock file :)

[zifeo]

huge work!