feat: add caching to resolver

[shubhbapna]

fixes #359

Summarizing the needs from #358 (and from our previous calls)

• we shouldn't use caching for install type requirements because we always want the latest version that matches the reqs and constraints and we cannot guarantee that the latest version will exist in the cache. For example:

  • first we resolve numpy<2 which ends up populating the cache with say numpy==1. Then we want to resolve numpy>=1 as an install type req. if we end up using the cache it would return numpy==1 even though there is a numpy==2 that we can use.
  • we want install type reqs to be the latest possible version so that they have the latest possible cve fixes in them

• the cache is something internal to the resolver and should not be influenced directly by the caller of the resolver

[shubhbapna]

@dhellmann anymore changes required?