misc(blob/service)!: return single ErrNotFound in GetAll

[vgonkivs]

Resolves #3192

[Wondertan]

This is technically API breaking as someone could depend on the error, so we should mark it as so

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 44.50%. Comparing base (2469e7a) to head (bc24637). Report is 134 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3223      +/-   ##
==========================================
- Coverage   44.83%   44.50%   -0.33%     
==========================================
  Files         265      273       +8     
  Lines       14620    15402     +782     
==========================================
+ Hits         6555     6855     +300     
- Misses       7313     7738     +425     
- Partials      752      809      +57     

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[jcstein]

This is technically API breaking as someone could depend on the error, so we should mark it as so

Isn't this breaking? why were tags and ! removed?

[vgonkivs]

Reworked to non-breaking.

[jcstein]

makes sense, thanks! and in this feature, if there are no blobs, empty vector is returned? is there anything else that changes from a user perspective?

[vgonkivs]

if there are no blobs, empty vector is returned?

Yeap

is there anything else that changes from a user perspective?

1. Single ErrNotFound is returned in case blobs won't be found in multiple namespaces.
2. The result blobs will be grouped by namespace but we don't guarantee the order corresponding to namespaces in the request.(not changed but worth adding to docs imo)
3. ErrNotFound will not be returned in case of multiple positive + multiple negative responses. If during [n1,n2,n3,n4] we will find only [n1,n3], they will be returned without any error.
4. For other type of errors(e.g. networking), we can return both found blobs + merged from all other requests error

[vgonkivs]

Hey @jcstein, we discussed internally with @renaynay and agreed to return the break label bc the behaviour has been slightly changed.