Added directory streaming feature

[marcoSanti]

This pull request implements the necessary changes to the CapioFile class to enable streaming for directory content. The primary updates include:

• CapioFile Class: Added _data_avail_cv.notify_all() within the incrementDirectoryFileCount() method to ensure waiting threads are signaled correctly;
• POSIX Read Cache: Updated the logic to ensure that SYS_getdents calls bypass the cache. Since a typical dirent entry is approximately 280 bytes, it is inefficient to wait for a full 256 KB cache line to be populated.

Additionally, this PR includes server-side unit tests to verify dynamic streaming over directory content and prevent future regressions.

[codecov]

Codecov Report

❌ Patch coverage is 81.81818% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 64.70%. Comparing base (1e8b2ef) to head (9c1504c).
⚠️ Report is 1 commits behind head on master.

Files with missing lines	Patch %	Lines
capio/posix/utils/cache.hpp	0.00%	0 Missing and 1 partial ⚠️
capio/server/src/storage_manager.cpp	50.00%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #218      +/-   ##
==========================================
+ Coverage   64.59%   64.70%   +0.10%     
==========================================
  Files          73       73              
  Lines        3161     3165       +4     
  Branches     1965     1966       +1     
==========================================
+ Hits         2042     2048       +6     
+ Misses        880      371     -509     
- Partials      239      746     +507     

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

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[GlassOfWhiskey]

LGTM