Cache DNS responses for IpaClients

[akoshelev]

Our client is not a general-purpose HTTP client and talks to only limited subset of services, so caching will be effective here to prevent overloading DNS

[akoshelev]

I am seeing test hangs when running them locally, so I don't think this is ready to be merged. I can't figure out why it may be caused by the cache (we only resolve localhost and I confirmed that it does not block on Dashmap) but it is always DNS...

[codecov]

Codecov Report

Attention: Patch coverage is 95.34884% with 4 lines in your changes missing coverage. Please review.

Project coverage is 93.24%. Comparing base (fa74e23) to head (fd6f313).

Files with missing lines	Patch %	Lines
ipa-core/src/net/client/dns.rs	95.18%	4 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1496      +/-   ##
==========================================
+ Coverage   93.23%   93.24%   +0.01%     
==========================================
  Files         237      238       +1     
  Lines       43534    43617      +83     
==========================================
+ Hits        40587    40672      +85     
+ Misses       2947     2945       -2     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.