fix: `missing_debug_implementations`

[JonathanWoollett-Light]

Summary of the PR

Sets missing_debug_implementations to deny and adds missing std::fmt::Debug implementations.

When tracing/logging/debugging a program it is common to debug print inputs and outputs of function, to do this generally dependencies need to offer std::fmt::Debug implementations.

I won't repeat what is written under missing_debug_implementations which gives some more explanation.

Requirements

Before submitting your PR, please make sure you addressed the following requirements:

• [x] All commits in this PR are signed (with git commit -s), and the commit message has max 60 characters for the summary and max 75 characters for each description line.
• [x] All added/changed functionality has a corresponding unit/integration test.
• [x] All added/changed public-facing functionality has entries in the "Upcoming Release" section of CHANGELOG.md (if no such section exists, please create one).
• [x] Any newly added unsafe code is properly documented.

[andreeaflorescu]

@JonathanWoollett-Light do you still want to get this merged? If yes, can you fix the conflicts? Otherwise please close the PR.