Package registration takes too long

[cohaereo]

On a fast drive this takes about 2-3 seconds, but hard drives suffer hard when building the package manager's tag lookup index (TLI). This is especially annoying during fast development iteration cycles

Some potential solutions i've come up with:

• On-disk TLI cache (build the index once, then save it to disk, similar to the package path cache)
• Lazy loaded TLI (only load entries into TLI once the package is loaded for the first time)
  • May incur a small delay when accessing packages for the first time, but is still way faster than having to index every package
  • Limits direct entry lookup (eg. through the get_entry API)
• ???

The on-disk cache and lazy loaded TLI can potentially be combined as well