Update flamed enemies with an overlay like ice (rebased) (#3242)

* Update flamed enemies [WIP]

Graphics are by @Rusty-Box !

* Fishy fire

* More common forest flamers

* Finish adding fire sprites

* Make the charr timed by dt_sec

* badguy.cpp: fix Marty's issues

* fix weird offsets

* badguy.cpp: code quality

* more offset fixes

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Co-authored-by: Daniel Ward <[email protected]>

fixes #2717

Author: Hypernoot