Progress callbacks fire for all meta-request types

[graebm]

Description of changes:

• progress_callback is now invoked for all meta-request types.
  • Previously, it was only invoked for multi-part PUT and multi-part COPY. It wasn't invoked when PUT or COPY was done as a single-part operation, and wasn't invoked for any type of GET.
• progress_callbacks now fire sequentially, and do not overlap with the meta-request's other callbacks.
  • Previously, progress_callbacks could fire on different threads and overlap with each other (and overlap the body_callback).
  • TODO: telemetry_callback can still overlap with other callbacks. We should give it the same treatment.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[codecov-commenter]

Codecov Report

Merging #344 (6ea1c3f) into main (75788fb) will decrease coverage by 0.02%.
The diff coverage is 97.41%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #344      +/-   ##
==========================================
- Coverage   89.52%   89.51%   -0.02%     
==========================================
  Files          17       17              
  Lines        4897     4929      +32     
==========================================
+ Hits         4384     4412      +28     
- Misses        513      517       +4     

Files Changed	Coverage Δ
source/s3_auto_ranged_get.c	97.88% <91.66%> (-0.67%)	⬇️
source/s3_meta_request.c	92.60% <96.66%> (-0.74%)	⬇️
source/s3_auto_ranged_put.c	92.25% <100.00%> (+0.06%)	⬆️
source/s3_client.c	87.98% <100.00%> (-0.05%)	⬇️
source/s3_copy_object.c	82.83% <100.00%> (+1.69%)	⬆️
source/s3_default_meta_request.c	94.59% <100.00%> (+0.34%)	⬆️
source/s3_request.c	95.23% <100.00%> (+0.04%)	⬆️
source/s3_util.c	98.66% <100.00%> (ø)