Fix run queue item ids to string type

[KyleGoyette]

There were some issues from returning ints as the id type for run queue items. Since we expect a string, this just corrects all of them to strings.

[codecov]

Codecov Report

Merging #74 (aaa12cf) into main (ce77319) will not change coverage.
The diff coverage is 0.00%.

@@           Coverage Diff           @@
##             main      #74   +/-   ##
=======================================
  Coverage   10.29%   10.29%           
=======================================
  Files           7        7           
  Lines        1642     1642           
=======================================
  Hits          169      169           
  Misses       1473     1473           

Flag	Coverage Δ
unittest	10.29% <0.00%> (ø)

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Impacted Files	Coverage Δ
src/yea_wandb/mock_server.py	0.00% <0.00%> (ø)

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