resprites most tanks (tgstation#76914)

## About The Pull Request
i resprited a bunch of various tanks to have nicer shading using
imaginos' base
you can see the before and after for each tank here:

![image](https://github.com/tgstation/tgstation/assets/110322848/866317e4-03e9-4d8a-91b7-cb64cd897ad4)
(now includes plasmatank)
## Why It's Good For The Game
the previous tank sprites held up for a while, but they have dark grey
outlines and their shading has become a bit dated, so it's nice to
freshen them up. this brings them closer to some of the nicer sprites in
the game, while preserving their shape, as the bases for them were quite
good.
## Changelog

:cl:
image: updated most tank sprites. 
/:cl: