better error when offset doesn't match expected

[jkeifer]

Error now contains expected_offset and provided_offset instead of the ambiguous offset.

[codecov-commenter]

Codecov Report

Merging #34 (e716b33) into main (ed96cf3) will not change coverage.
The diff coverage is 100.00%.

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@@           Coverage Diff           @@
##             main      #34   +/-   ##
=======================================
  Coverage   94.02%   94.02%           
=======================================
  Files           8        8           
  Lines         335      335           
=======================================
  Hits          315      315           
  Misses         20       20           

Files Changed	Coverage Δ
src/drf_chunked_upload/views.py	94.57% <100.00%> (ø)

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