chore: uploader can append

[fracasula]

Description

We can append if:

• source is not an ETL source
• source it's not a replay
• source category is not in a specific set
• we are in append mode

Additional changes

• removed duplicated mocked uploader in favour of MockGen

TODOs

• use Uploader.CanAppend() in the other integrations that support APPEND mode

Linear Ticket

< Linear 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.

[fracasula]

Blocked by rudderlabs/rudder-go-kit#108

[codecov]

Codecov Report

Patch coverage: 63.35% and project coverage change: -0.04% ⚠️

Comparison is base (60749af) 68.91% compared to head (df6fb3b) 68.88%.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3805      +/-   ##
==========================================
- Coverage   68.91%   68.88%   -0.04%     
==========================================
  Files         349      350       +1     
  Lines       52370    52499     +129     
==========================================
+ Hits        36092    36162      +70     
- Misses      13978    14032      +54     
- Partials     2300     2305       +5     

Files Changed	Coverage Δ
warehouse/jobs/jobs.go	7.40% <0.00%> (-0.29%)	⬇️
warehouse/utils/utils.go	85.23% <ø> (ø)
warehouse/validations/validate.go	81.26% <15.78%> (+0.39%)	⬆️
warehouse/internal/mocks/utils/mock_uploader.go	65.57% <65.57%> (ø)
warehouse/integrations/deltalake/deltalake.go	74.49% <100.00%> (ø)
warehouse/integrations/snowflake/snowflake.go	60.45% <100.00%> (-0.11%)	⬇️
warehouse/upload.go	71.60% <100.00%> (+0.19%)	⬆️

... and 8 files with indirect coverage changes

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[fracasula]

@lvrach this one can potentially be merged if we temporarily remove the -race from the Makefile. I still need another approval though.

[fracasula]

@lvrach kind reminder that this is ready to review and passing.