Camera: Fix assorted deprecation and formatting warnings

- Remove deprecated iterator base class from RingBuffer's iterator
- Backport C++23's enum to_underlying() function and use it to fix
  a pile of formatting conversion warnings when logging enum values
- Also fix a few other formatting specifiers

Test: Builds
Flag: EXEMPT refactoring
Change-Id: I9f6560f7fe893654aba5fe12fea8e14d326e5a28