adding initial docker support for agenthost

[rysweet]

Why are these changes needed?

Related issue number

Checks

• I've included any doc changes needed for https://microsoft.github.io/autogen/. See https://microsoft.github.io/autogen/docs/Contribute#documentation to build and test documentation locally.
• I've added tests (if relevant) corresponding to the changes introduced in this PR.
• I've made sure all auto checks have passed.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 76.51%. Comparing base (559aea9) to head (a1e0c21).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5479      +/-   ##
==========================================
- Coverage   78.35%   76.51%   -1.85%     
==========================================
  Files         167      206      +39     
  Lines        9926    11040    +1114     
  Branches        0      150     +150     
==========================================
+ Hits         7778     8447     +669     
- Misses       2148     2496     +348     
- Partials        0       97      +97     

Flag	Coverage Δ
unittests	76.51% <ø> (-1.85%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

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