Add negative cache for folders

[Tulsishah]

Description

We're adding a negative stat cache for folders to reduce GCS calls for negative entries. Although we initially implemented functions for this, we encountered corner cases that needed addressing, which didn't fit within the release timeframe. Therefore, @ankitaluthra1 and I decided to postpone this feature as a post-launch item, as it's not a release blocker.

Scenarios:

We can say that StatObject(A) will cache a negative folder entry for "A" because "A" can only exist as an object, not a folder. Similarly, GetFolder(A/) will cache a negative object entry for "A/" as it can only exist as a folder, not an object, in HNS with GCSFuse.

Other changes

• Replaced the negative cache entry with an invalidation step in the DeleteFolder function. This change aligns DeleteFolder with the existing DeleteObject function, which also uses invalidation. (Because adding negative cache was changing behaviour compare to object deletion)
• Added logic to erase cache entries for renamed folders as part of the stale data cleanup process. Added stat call to fill negative cache in composite test.
• Implicit_dir test changes - The test were failing due to all the tests were performing operations on single folder. One test were filling negative cache and second one try to access it. So I created separate folder for each test to avoid failure.

Link to the issue in case of a bug fix.

NA

Testing details

1. Manual - NA
2. Unit tests - NA
3. Integration tests - Automated

[codecov]

Codecov Report

Attention: Patch coverage is 83.33333% with 4 lines in your changes missing coverage. Please review.

Project coverage is 78.14%. Comparing base (4f40a8f) to head (a1d930a).
Report is 12 commits behind head on master.

Files with missing lines	Patch %	Lines
internal/storage/caching/fast_stat_bucket.go	76.47%	2 Missing and 2 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2530      +/-   ##
==========================================
- Coverage   78.83%   78.14%   -0.70%     
==========================================
  Files         106      107       +1     
  Lines       11700    11777      +77     
==========================================
- Hits         9224     9203      -21     
- Misses       1995     2094      +99     
+ Partials      481      480       -1     

Flag	Coverage Δ
unittests	78.14% <83.33%> (-0.70%)	⬇️

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