APPS-2006 Add storage connectivity checks

[korotkov-aerospike]

Features

• Storage Connectivity: Added connectivity checks for S3, Azure, and GCP storage backends. The service now verifies access to the configured bucket/container upon initialization, failing fast if the storage is unreachable.
• Azure Resilience: Implemented the global storage retry policy (max retries, delay, backoff) for the Azure Blob Storage client (was missing previously for some auth types)
• Azure Auth are using pointer receivers now, to pass gob serialization-deserialization.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 89.70588% with 7 lines in your changes missing coverage. Please review.
✅ Project coverage is 54.11%. Comparing base (5a0af47) to head (282ffb6).

Files with missing lines	Patch %	Lines
pkg/service/storage/azure.go	81.08%	6 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##               v3     #473      +/-   ##
==========================================
+ Coverage   51.69%   54.11%   +2.42%     
==========================================
  Files          84       84              
  Lines        5515     5564      +49     
==========================================
+ Hits         2851     3011     +160     
+ Misses       2440     2318     -122     
- Partials      224      235      +11     

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