chore: fix namespace bug

[cisse21]

Description

Fixing the bug introduced in the previous refactoring of getNamespace function which returned an empty namespace even though there was a valid namespace present in the schema table also adding tests for the same

Notion Ticket

Notion Link

Security

• The code changed/added as part of this pull request won't create any security issues with how the software is being used.

[codecov]

Codecov Report

Patch coverage: 86.66% and project coverage change: +0.22 🎉

Comparison is base (0d9af35) 53.55% compared to head (e5dac9d) 53.78%.

Additional details and impacted files

@@                Coverage Diff                @@
##           release/1.7.x    #3110      +/-   ##
=================================================
+ Coverage          53.55%   53.78%   +0.22%     
=================================================
  Files                350      350              
  Lines              54452    54456       +4     
=================================================
+ Hits               29163    29287     +124     
+ Misses             23633    23506     -127     
- Partials            1656     1663       +7     

Impacted Files	Coverage Δ
warehouse/warehouse.go	13.44% <86.66%> (+1.85%)	⬆️

... and 9 files with indirect coverage changes

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[lvrach]

Please provide more context, what is the bug and the intended fix.

[cisse21]

Please provide more context, what is the bug and the intended fix.

Updated the description now