fix(sdk): unify offline and online mode during init and fix multiprocess attach

[kptkin]

…xisting run (#5144)

Fixes WB-NNNN
Fixes #5071

Description

What does the PR do?

TODO:

• unify deliver_run and publish_run
• move attach handling from sender to handler
• unify offline_run and online_run in the run class

Testing

How was this PR tested?

Checklist

• Include reference to internal ticket "Fixes WB-NNNN" and/or GitHub issue "Fixes #NNNN" (if applicable)
• Ensure PR title compliance with the conventional commits standards

[codecov]

Codecov Report

Merging #5296 (3c70bb8) into main (ef309c3) will increase coverage by 0.00%.
The diff coverage is 96.82%.

❗ Current head 3c70bb8 differs from pull request most recent head d8cf045. Consider uploading reports for the commit d8cf045 to get more accurate results

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #5296   +/-   ##
=======================================
  Coverage   82.47%   82.48%           
=======================================
  Files         322      321    -1     
  Lines       39235    39180   -55     
=======================================
- Hits        32360    32317   -43     
+ Misses       6875     6863   -12     

Flag	Coverage Δ
functest	56.16% <79.36%> (+0.01%)	⬆️
unittest	71.78% <76.19%> (-0.02%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
wandb/sdk/internal/sender.py	93.12% <ø> (-0.07%)	⬇️
wandb/sdk/wandb_init.py	87.32% <93.33%> (+0.17%)	⬆️
wandb/sdk/interface/interface.py	96.12% <100.00%> (+0.02%)	⬆️
wandb/sdk/internal/handler.py	94.94% <100.00%> (+0.09%)	⬆️
wandb/sdk/wandb_run.py	91.79% <100.00%> (-0.04%)	⬇️

... and 24 files with indirect coverage changes

[raubitsj]

LGTM gnarly codepath, nice fix

[kptkin]

/suggest-title

[github-actions]

Suggested title:

fix(sdk): unify offline and online mode during init and fix multiprocess attach