Fixes renwick shield generators incorrectly using power

- Shield generators now correctly use power according to actual field strength.
- Minimal shield dissipation rate now corresponds with 1 renwick field (changed from 10, which technically caused shields to always use max upkeep power ignoring field strength completely)
Canister Logs

Opening a non-empty canister now produces an admin message, not only a log note on the canister itself.
Fixes missing icons for xenoarchaeology items EXCEPT for the energy guns.
Fixes the xenoarch eguns.

This was done by making the xenoarch eguns new subtypes with different update_icon() procs than the regular eguns. The new subtypes are in finds_eguns.dm
Fixes a bug where core samplers dispensed bags that you could not take rock slivers out of.
Fixes paper bundles burning strangely with a match and burning one paper at a time, leaving a lone paperclip at the end that would eat any paper added to it and never let that paper be interacted with. Paper bundles now burn the same way (whole thing at once) no matter what you're burning it with, rather than only burning that way with a lighter.
Merge pull request #7077 from MagmaRam/bugfix

Fixes xenoarch find sprites and core samplers not working
Merge pull request #7064 from PsiOmegaDelta/CanisterLogs

Canister Logs
Merge pull request #7055 from atlantiscze/dem-shields

Fixes renwick shield generators incorrectly using power
Fixes #7068
Merge pull request #7081 from MagmaRam/bugfix

Fixes paper bundles not burning properly with a match
Merge pull request #7087 from mwerezak/master

Fixes #7086