use neww uuids for new builds folders in cache

[memsharded]

Changelog: Feature: Allow step-into dependencies debugging for packages built locally with --build
Changelog: Feature: Allow non relocatable, locally built packages with upload_policy="skip" and build_policy="missing"
Docs: conan-io/docs#3210

Close #13799
Close #13237

This PRs does the following:

• For the package binaries built in the cache, use a random UUID to compute their folder. Such folder will be different each time it is built, but it is also expected that the final package-revision would be different so it shouldn't be a big deal
• The same can not be done for recipes, because creating a new folder with a random uuid each time a recipe is exported would completely invalidate the source folder, making the caching of the sources in the cache completely useless (we could use a mechanism similar to the build_id lookup in the cache, but seems overkill)
• The downloaded packages still get downloaded to the same folder, not using uuid, but hashing the full reference including the package-revision, so they are always located in the same place (could help with compilation caches as ccache)
• It was necessary to augment a but the conan cache clean, because builds that not succeed will leave extra trailing folders that can't be removed with conan remove as they don't have a final reference