Replace custom deepdiff wrapper scripts with deepdiff CLI

[huddlej]

Context

Augur's functional tests rely on a lightweight wrapper script around DeepDiff, scripts/diff_jsons.py, to support comparisons between JSONs. Augur's dev requirements specify DeepDiff >=4.3.2.

However, version 5.2.0 of DeepDiff introduced a command line interface that provides the same functionality (and much more!) than the simple wrapper script.

Description

We should consider pinning our minimum DeepDiff version at 5.2.0[cli], replacing all uses of diff_jsons.py with the equivalent deep diff command, and removing the diff_jsons.py script. The CLI also supports comparisons of other file types like CSV (with the installation of additional Python libraries) which might generally improve our functional tests.

Examples

# Original command.
python3 scripts/diff_jsons.py --significant-digits 4 expected.json observed.json

# With the DeepDiff CLI.
deep diff --significant-digits 4 expected.json observed.json