[Feature Idea] Result Caching

[albertalef]

Problem: Scripts that call the same expensive command multiple times waste time re-executing identical operations, especially with API calls or slow queries.

Solution: Add _cache option to cache command results for a specified duration in seconds, returning cached results for subsequent identical calls.

sh.curl(api_url, _cache: 60)  # cache for 60 seconds

data1 = sh.curl(api_url, _cache: 60)
data2 = sh.curl(api_url, _cache: 60)  # instant, from cache

# Force refresh
sh.curl(api_url, _cache: 60, _refresh_cache: true)