### Description
Given all the shell files that now exist in the repo, would be nice to
have linting/formatting around them (in addition to the existing
shellcheck which doesn't do anything to format the shell code). This PR
introduces `shfmt` to both check for changes and apply formatting when
the associated make targets are called.
- Updates CI to install tesseract version 5.3.0 (better than 4.x in various ways incl. perf.).
- Adds azure expected output fixtures for more useful reference points and as a repro for Some PDF's with scanned images return empty elements #346 .
- Adds a script to regenerate ingest test fixtures that is run in an ubuntu docker container (like CI), with the same version of tesseract. See the comments in scripts/ingest-test-fixtures-update.sh for details.
- Updates expected outputs with above script.
- Updates individual test-ingest scripts to update expected .json output if OVERWRITE_FIXTURES=true.
